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Diffstat (limited to 'giflib-4.1.6/doc')
42 files changed, 6459 insertions, 0 deletions
diff --git a/giflib-4.1.6/doc/GifFileType.png b/giflib-4.1.6/doc/GifFileType.png Binary files differnew file mode 100644 index 0000000..11ccaaa --- /dev/null +++ b/giflib-4.1.6/doc/GifFileType.png diff --git a/giflib-4.1.6/doc/Makefile.am b/giflib-4.1.6/doc/Makefile.am new file mode 100644 index 0000000..0918e17 --- /dev/null +++ b/giflib-4.1.6/doc/Makefile.am @@ -0,0 +1,41 @@ +UTILHELP = gif2bgi.html \ + gif2epsn.html \ + gif2herc.html \ + gif2iris.html \ + gif2ps.html \ + gif2rgb.html \ + gif2rle.html \ + gif2x11.html \ + gifasm.html \ + gifbg.html \ + gifburst.html \ + gifclip.html \ + gifclrmp.html \ + gifcolor.html \ + gifcomb.html \ + gifcompose.html \ + giffiltr.html \ + giffix.html \ + gifflip.html \ + gifhisto.html \ + gifinter.html \ + gifinto.html \ + gifovly.html \ + gifpos.html \ + gifrotat.html \ + gifrsize.html \ + gifspnge.html \ + giftext.html \ + gifwedge.html \ + icon2gif.html \ + raw2gif.html \ + rgb2gif.html \ + rle2gif.html \ + text2gif.html +LIBRARYHELP = GifFileType.png \ + gif89.txt \ + gif_lib.html \ + index.html \ + liberror.html \ + lzgif.txt +EXTRA_DIST = $(UTILHELP) $(LIBRARYHELP) diff --git a/giflib-4.1.6/doc/Makefile.in b/giflib-4.1.6/doc/Makefile.in new file mode 100644 index 0000000..d2c38ac --- /dev/null +++ b/giflib-4.1.6/doc/Makefile.in @@ -0,0 +1,374 @@ +# Makefile.in generated by automake 1.10 from Makefile.am. +# @configure_input@ + +# Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, +# 2003, 2004, 2005, 2006 Free Software Foundation, Inc. +# This Makefile.in is free software; the Free Software Foundation +# gives unlimited permission to copy and/or distribute it, +# with or without modifications, as long as this notice is preserved. + +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY, to the extent permitted by law; without +# even the implied warranty of MERCHANTABILITY or FITNESS FOR A +# PARTICULAR PURPOSE. + +@SET_MAKE@ +VPATH = @srcdir@ +pkgdatadir = $(datadir)/@PACKAGE@ +pkglibdir = $(libdir)/@PACKAGE@ +pkgincludedir = $(includedir)/@PACKAGE@ +am__cd = CDPATH="$${ZSH_VERSION+.}$(PATH_SEPARATOR)" && cd +install_sh_DATA = $(install_sh) -c -m 644 +install_sh_PROGRAM = $(install_sh) -c +install_sh_SCRIPT = $(install_sh) -c +INSTALL_HEADER = $(INSTALL_DATA) +transform = $(program_transform_name) +NORMAL_INSTALL = : +PRE_INSTALL = : +POST_INSTALL = : +NORMAL_UNINSTALL = : +PRE_UNINSTALL = : +POST_UNINSTALL = : +build_triplet = @build@ +host_triplet = @host@ +subdir = doc +DIST_COMMON = $(srcdir)/Makefile.am $(srcdir)/Makefile.in +ACLOCAL_M4 = $(top_srcdir)/aclocal.m4 +am__aclocal_m4_deps = $(top_srcdir)/configure.ac +am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \ + $(ACLOCAL_M4) +mkinstalldirs = $(install_sh) -d +CONFIG_HEADER = $(top_builddir)/config.h +CONFIG_CLEAN_FILES = +SOURCES = +DIST_SOURCES = +DISTFILES = $(DIST_COMMON) $(DIST_SOURCES) $(TEXINFOS) $(EXTRA_DIST) +ACLOCAL = @ACLOCAL@ +AMTAR = @AMTAR@ +AR 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@datarootdir@ +docdir = @docdir@ +dvidir = @dvidir@ +exec_prefix = @exec_prefix@ +host = @host@ +host_alias = @host_alias@ +host_cpu = @host_cpu@ +host_os = @host_os@ +host_vendor = @host_vendor@ +htmldir = @htmldir@ +includedir = @includedir@ +infodir = @infodir@ +install_sh = @install_sh@ +libdir = @libdir@ +libexecdir = @libexecdir@ +localedir = @localedir@ +localstatedir = @localstatedir@ +mandir = @mandir@ +mkdir_p = @mkdir_p@ +oldincludedir = @oldincludedir@ +pdfdir = @pdfdir@ +prefix = @prefix@ +program_transform_name = @program_transform_name@ +psdir = @psdir@ +sbindir = @sbindir@ +sharedstatedir = @sharedstatedir@ +srcdir = @srcdir@ +sysconfdir = @sysconfdir@ +target_alias = @target_alias@ +top_builddir = @top_builddir@ +top_srcdir = @top_srcdir@ +UTILHELP = gif2bgi.html \ + gif2epsn.html \ + gif2herc.html \ + gif2iris.html \ + gif2ps.html \ + gif2rgb.html \ + gif2rle.html \ + gif2x11.html \ + gifasm.html \ + gifbg.html \ + gifburst.html \ + gifclip.html \ + gifclrmp.html \ + gifcolor.html \ + gifcomb.html \ + gifcompose.html \ + giffiltr.html \ + giffix.html \ + gifflip.html \ + gifhisto.html \ + gifinter.html \ + gifinto.html \ + gifovly.html \ + gifpos.html \ + gifrotat.html \ + gifrsize.html \ + gifspnge.html \ + giftext.html \ + gifwedge.html \ + icon2gif.html \ + raw2gif.html \ + rgb2gif.html \ + rle2gif.html \ + text2gif.html + +LIBRARYHELP = GifFileType.png \ + gif89.txt \ + gif_lib.html \ + index.html \ + liberror.html \ + lzgif.txt + +EXTRA_DIST = $(UTILHELP) $(LIBRARYHELP) +all: all-am + +.SUFFIXES: +$(srcdir)/Makefile.in: $(srcdir)/Makefile.am $(am__configure_deps) + @for dep in $?; do \ + case '$(am__configure_deps)' in \ + *$$dep*) \ + cd $(top_builddir) && $(MAKE) $(AM_MAKEFLAGS) am--refresh \ + && exit 0; \ + exit 1;; \ + esac; \ + done; \ + echo ' cd $(top_srcdir) && $(AUTOMAKE) --gnu doc/Makefile'; \ + cd $(top_srcdir) && \ + $(AUTOMAKE) --gnu doc/Makefile +.PRECIOUS: Makefile +Makefile: $(srcdir)/Makefile.in $(top_builddir)/config.status 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make to not export all variables. +# Otherwise a system limit (for SysV at least) may be exceeded. +.NOEXPORT: diff --git a/giflib-4.1.6/doc/gif2bgi.html b/giflib-4.1.6/doc/gif2bgi.html new file mode 100644 index 0000000..7640cbf --- /dev/null +++ b/giflib-4.1.6/doc/gif2bgi.html @@ -0,0 +1,136 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gif2bgi</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gif2bgi</H1></CENTER> + +A program to display images saved as GIF files on IBM PC display devices using +the BGI (Borland) driver interface.<P> + +The program operates as follows:<P> + +<OL> +<LI> +Reads the GIF file header and determines the image size.<P> + +<LI> +Dynamically allocates enough memory to hold all the image internally. +One byte per pixel is always allocated, so a little bit more than +width*height (of screen, not image) bytes are required.<P> + +<LI> +Reads all the image in. Interlaced images are read in correctly, although +they are displayed sequentially.<P> + +<LI> +Display first image using the defaults as set by the command line option.<P> + +<LI> +Goes to interactive mode. For a full description of the interactive mode +see below.<P> +</OL> + +<H1>Usage:</H1> + +<pre> +gif2bgi [-q] [-d BGI dir] [-u driver] [-z zoom] [-b] [-h] gif-file +</pre> + +If no GIF is given, gif2bgi will try to read a GIF file from stdin.<P> + +<H1>Memory required:</H1> + +Screen. + +<H1>Options:</H1> +<DL> +<DT> [-q] +<DD> Quiet mode. Default off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-d BGI Directory] +<DD> Where we should look for default drivers (as supplied by Borland). + For example '-d c:/tc/bgi'.<P> + +<DT> [-u driver] +<DD> Specifies a user-defined BGI driver. If for example + you have a BGI driver for your special vga called MYVGA.BGI and you want + to run it in mode 2, then type '-u c:/tc/bgi/myvga.2'. Note the absolute + path to the driver must be specified. Also note that we use '/' and not + '\' so they won't be treated as options.<P> + +<DT> [-z zoom] +<DD> Sets zoom factor of the view. Zoom factor should be + power of 2 up to 256. Default is 1 (no zoom).<P> + +<DT> [-h] +<DD> Print one line of command-line help, similar to Usage above.<P> +</DL> + +<H1>Interactive mode:</H1> + +Once the image is displayed, the gif2bgi program goes into interactive mode +which recognizes the following commands:<P> + +<DL> +<DT> C - get Color and position +<DD> In this submenu, a cursor appears and the location and color of the + pixel underneath it are printed. The 4 arrows may be used (shifted for + faster movement) to move the cursor. Any other key will abort this submode.<P> + +<DT> D - zoom Down +<DD> Zoom down by factor of 2 unless current zoom factor is 1.<P> + +<DT> R - Redraw +<DD> Redraw the image.<P> + +<DT> S - print Status +<DD> Print status of image and program.<P> + +<DT> U - zoom Up +<DD> Zoom up by factor of 2 unless current zoom factor is 256.<P> + +<DT> arrow keys +<DD> The 4 arrow keys can be used to pan in the desired direction, if the image + overflows in that direction. If the image fits into the screen, arrow + keys are ignored. The panning steps are 1/2 screen if not on image end.<P> + +<DT> SPC - abort +<DD> Space bar may be used to abort current image drawing.<P> + +<DT> ESC - abort +<DD> Escape may be used to abort current image drawing. +</DL> + + +<H1>Notes:</H1> + +This program is useless in a Unix environment and is not normally +built there.<P> + +No color quantization is used in this program; thus, if a GIF image has more +colors than the BGI driver support, this program will abort.<P> + +This driver is optimized for drivers with one byte per pixel (256 colors) +and will run MUCH faster on such drivers.<P> + +<H1>Bugs:</H1> + +For some reason I could not figure out, on my ATI wonder card, int 10h call +10h (AH = AL = 10h) to set the color registers sometimes result with wrong +colors. Direct access of the card registers gives correct results.<P> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> + diff --git a/giflib-4.1.6/doc/gif2epsn.html b/giflib-4.1.6/doc/gif2epsn.html new file mode 100644 index 0000000..fc102b7 --- /dev/null +++ b/giflib-4.1.6/doc/gif2epsn.html @@ -0,0 +1,98 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gif2bgi</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gif2epsn</H1></CENTER> + +A program to dump images saved as GIF files on Epson type printers.<P> + +<H1>Usage:</H1> + +<pre> +gif2epsn [-q] [-d dither] [-t bw] [-m map] [-i] [-n] [-p printer] [-h] gif-file +</pre> + +If no gif-file is given, Gif2Epsn will try to read a GIF file from stdin.<p> + + +<H1>Memory required:</H1> + +Screen. + +<H1>Options:</H1> + +<DL> +<DT>[-q] +<DD> Quiet mode. Default off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT>[-d dither] +<DD> Sets size of dithering matrix, where DitherSize can be + 2,3 or 4 only (for 2x2, 3x3 and 4x4 dithering matrices). Default is 2. + Note image will be displayed in this mode only if the mapping + option (see -m) selected this mode.<P> + +<DT> [-t bw] +<DD> Sets threshold level for B&W mapping in percent. + This threshold level is used in the different mappings as selected via -m. + Default is 19%.<P> + +<DT> [-m map] +<DD> Select method to map colors to B&W. Mapping can be: + + <DL> + <DT>0<DD> + Every none background color is considered foreground (white color but + is drawn as black by printer, unless -i is specified).<P> + + <DT>1<DD> + If 0.3 * RED + 0.59 * GREEN + 0.11 * YELLOW > BW the pixel is + considered white color.<P> + + <DT>2<DD> + Colors are mapped as in 1, and use dithering of size as defined using + -d option. BWthreshold is used here as scaler.<P> + </DL><P> + +The default is option 0.<P> + +<DT> [-i] +<DD> Invert the image, i.e. black -> white, white -> black.<P> + +<DT> [-n] +<DD> Nicer image. Uses double-density feature of Epson printer. This + takes more time (and kills your ink cartridge faster...) but results + are usually better.<P> + +<DT> [-p printer] +<DD> Under Unix, output goes to stdout by default; under DOS, the + default is LPT1:. With this switch you can specify the output + target.<P> + +<DT> [-h] +<DD> print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Notes:</H1> + +The output has an aspect ratio of 1, so a square image will be square in +hardcopy as well.<P> + +The widest image can be printed is 640 pixels, on 8 inch paper. You +probably will need to flip wider images, if height is less than that: +`<a href="gifflip.html">gifflip</a> -r x29.gif | gif2epsn'. Wider +images will be clipped.<P> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gif2herc.html b/giflib-4.1.6/doc/gif2herc.html new file mode 100644 index 0000000..26afe0c --- /dev/null +++ b/giflib-4.1.6/doc/gif2herc.html @@ -0,0 +1,153 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gif2herc</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gif2herc</H1></CENTER> + +A program to display images saved as GIF files on an IBM PC Hercules +graphic card. The program operates as follows:<P> + +<OL> +<LI> +Read GIF file header and determine size of the image.<P> + +<LI> +Dynamically allocate enough memory to hold all the image internally. +One byte per pixel is always allocated, so a little bit more than +width*height (of screen, not image) bytes are required.<P> + +<LI> +Reads the image in. Interlaced images are read correctly, although +they are displayed sequentially.<P> + +<LI> +Display first image using the defaults as set by the command line option.<P> + +<LI> +Goes to interactive mode. For full description of the interactive mode +see below.<P> +</OL> + +<H1>Usage:</H1> + +<pre> +gif2herc [-q] [-d dither] [-z zoom] [-t bw] [-m map] [-i] [-b] [-h] gif-file +</pre> + +If no gif-file is given, gif2herc will try to read a GIF file from stdin.<P> + + +<H1>Memory required:</H1> + +Screen. + +<H1>Options:</H1> + +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-d dither] +<DD> Sets size of dithering matrix, where dither can be + 2,3 or 4 only (for 2x2, 3x3 and 4x4 dithering matrices). Default is 2. + Note: the image will be dithered only if the mapping (see -m) + selected dithering mode.<P> + +<DT> [-z zoom] +<DD> Sets zoom factor of the image. Zoom factor should be + power of 2 up to 256. Default is 1 (no zoom).<P> + +<DT> [-t bw] +<DD> Sets threshold level for B&W mapping in percent. + This threshold level is used in the different mappings as selected via -m. + Default is 19%.<P> + +<DT> [-m map] +<DD> Select method to map colors to B&W. Mapping can be: + + <DL> + <DT>0<DD> + Every non-background color is considered foreground (white). + + <DT>1<DD> + 0.3 * RED + 0.59 * GREEN + 0.11 * YELLOW > BWThreshold is considered white. + + <DT>2<DD> + Colors are mapped as in 1, and use dithering of size as defined using + -d option. BWthreshold is used here as scaler. + </DL> + +Default is option 0, which is much faster than the other two.<P> + +<DT> [-i] +<DD> Invert the image, i.e. black -> white, white -> black.<P> + +<DT> [-b] +<DD> Disable beeps. Every time the image is complete, or a wrong key was + presses, sound is generated. The -b option disables that.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Interactive mode:</H1> + +Once the image is displayed, the program goes into an interactive mode +which recognizes the following commands: + +<DL> +<DT> C - get Color and position +<DD> In this submenu, a cursor appears and the location and color of the + pixel underneath it are printed. The 4 arrows may be used (shifted for + faster movement) to move the cursor. Any other key will abort this + submode.<P> + + +<DT> D - zoom Down +<DD> Zoom down by factor of 2 unless current zoom factor is 1.<P> + +<DT>H - Increase dither matrix size +<DD>...unless current size is maximum (4), in which case size is set + to minimum (2).<P> + +<DT>I - Invert +<DD>Invert the image, i.e. white -> black, black -> white.<P> + +<DT>M - Method +<DD>Increment color -> BW mapping method, unless current method is maximum + (2), in which case method is set to minimum (0).<P> + +<DT> R - Redraw +<DD> Redraw the image.<P> + +<DT> S - print Status +<DD> Print status of image and program.<P> + +<DT> U - zoom Up +<DD> Zoom up by factor of 2 unless current zoom factor is 256.<P> + +<DT> arrow keys +<DD> The 4 arrow keys can be used to pan in the desired direction, if the image + overflows in that direction. If the image fits into the screen, arrow + keys are ignored. The panning steps are 1/2 screen if not on image end.<P> + +<DT> SPC - abort +<DD> Space bar may be used to abort current image drawing.<P> + +<DT> ESC - abort +<DD> Escape may be used to abort current image drawing.<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gif2iris.html b/giflib-4.1.6/doc/gif2iris.html new file mode 100644 index 0000000..dd6ae3b --- /dev/null +++ b/giflib-4.1.6/doc/gif2iris.html @@ -0,0 +1,52 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gif2iris</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gif2iris</H1></CENTER> + +A program to display images saved as GIF files under the +SGI NeWs window system.<P> + +<H1>Usage:</H1> + +<pre> +Gif2Iris [-q] [-f] [-p PosX PosY] [-f] [-h] gif-file +</pre> + +If no gif-file is given, Gif2Iris will try to read a GIF from stdin.<P> + +<H1>Memory required:</H1> + +Screen. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-f] +<DD> Force Gif2Iris to stay in foreground.<P> + +<DT> [-p PosX PosY] +<DD> Defines position of image on screen. By default the + program will prompt for position.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above..<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gif2ps.html b/giflib-4.1.6/doc/gif2ps.html new file mode 100644 index 0000000..7530d85 --- /dev/null +++ b/giflib-4.1.6/doc/gif2ps.html @@ -0,0 +1,71 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gif2ps</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gif2ps</H1></CENTER> + +GIF-to-PostScript conversion.<P> + +<H1>Usage:</H1> + +<pre> +gif2ps [-q] [-x] [-y] [-s sx sy] [-p px py] [-i] [-n copies] [-h] gif-file +</pre> + +If no gif-file is given, Gif2PS will try to read a GIF file from stdin.<P> + + +<H1>Memory required:</H1> + +Line. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-x] +<DD> Force image to be horizontal (`landscape mode'). By default image + will be positioned so it will be the biggest. If -x is given image will be + scaled to be biggest possible horizontally.<P> + +<DT> [-y] +<DD> Force vertical (`portrait mode'); analogous to -x.<P> + +<DT> [-s sx sy] +<DD> Force image size to be sx by sy inches. + If image will exit page dimensions, it will scream and die. + Page dimensions are 8.5 by 11.0 inches but only 7.5 by 9.0 are assumed to + be printable.<P> + +<DT> [-p pc py] +<DD> Force image lower left corner to be as px py. + If this would overrun the page's dimensions, it will scream and die.<P> + +<DT> [-i] +<DD> Image will be inverted (Black -> White and vice versa). + Mapping from colors is done by 0.3 * RED + 0.59 * GREEN + 0.11 * BLUE + and sometimes inverting the image will look better.<P> + +<DT> [-n copies] +<DD> Number of copies to print. 1 by default.<P> + +<DT> [-h] +<DD> Print one line of command help, similar to Usage above.<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gif2rgb.html b/giflib-4.1.6/doc/gif2rgb.html new file mode 100644 index 0000000..f47f1e8 --- /dev/null +++ b/giflib-4.1.6/doc/gif2rgb.html @@ -0,0 +1,55 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gif2rgb</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gif2rgb</H1></CENTER> + +A program to convert images saved as GIF to 24-bit RGB image(s). + + +<H1>Usage:</H1> + +<pre> +gif2rgb [-q] [-1] [-o OutFileName] [-h] gif-file +</pre> + +If no gif-file is given, Gif2RGB will try to read a GIF file from stdin.<P> + +<H1>Memory required:</H1> + +Screen. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-1] +<DD> Only one file in the format of RGBRGB... triplets (Each of R, G, B + is a byte) is being written. This file size is 3 * Width * Height. + If stdout is used for output, this option is implicitly applied. + The default (if not `-1') is 3 files with the names OutFileName.R, + OutFileName.G, OutFileName.B, each of which is Width * Height bytes.<P> + +<DT> [-o OutFileName] +<DD> specifies the name of the out file (see also `-1' above).<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gif2rle.html b/giflib-4.1.6/doc/gif2rle.html new file mode 100644 index 0000000..ec69248 --- /dev/null +++ b/giflib-4.1.6/doc/gif2rle.html @@ -0,0 +1,56 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gif2rle</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gif2rle</H1></CENTER> + +A program to convert images saved as GIF to RLE (Utah raster toolkit) +format.<p> + +<H1>Usage:</H1> + +<pre> +gif2rle [-q] [-a] [-h] gif-file +</pre> + +If no gif-file is given, Gif2Rle will try to read a GIF file from stdin.<p> + + +<H1>Memory required:</H1> + +Screen. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-a] +<DD> Add alpha channel (see rle document) to the output data file.<P> + +<DT> [-h] +<DD> Print one line command line help, similar to Usage above.<P> +</DL> + +<H1>Notes:</H1> + +This routine must be linked with the RLE toolkit library librle.a and +is not built by the normal distribution make. If you want to convert +images to RLE format, it is reasonable to assume you have this library +available.<p> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gif2x11.html b/giflib-4.1.6/doc/gif2x11.html new file mode 100644 index 0000000..5e26729 --- /dev/null +++ b/giflib-4.1.6/doc/gif2x11.html @@ -0,0 +1,59 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gif2x11</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gif2x11</H1></CENTER> + +A program to display images saved as GIF files under X window system.<P? + +<H1>Usage:</H1> + +<pre> +gif2x11 [-q] [-p PosX PosY] [-d Display] [-f] [-h] gif-file +</pre> + +If no gif-file is given, Gif2X11 will try to read a GIF file from stdin. +Note: this program does <em>not</em> read the X resource data base.<P> + +<H1>Memory required:</H1> + +Screen. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-p PosX PosY] +<DD> Set the position of image on screen. By default the + program will prompt for position.<P> + +<DT> [-d Display] +<DD> What X server should be connected to.<P> + +<DT> [-f] +<DD> Force attempt to allocate exact colors. This usually will result in a + very muddled image if not enough colors can be allocated; the rest of + them will be approximated by the closest one. By default the least bits + of the colors are stripped until success (in allocation) which looks much + better.<P> + +<DT> [-h] +<DD> Print one line command line help, similar to Usage above.<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gif89.txt b/giflib-4.1.6/doc/gif89.txt new file mode 100644 index 0000000..9516eec --- /dev/null +++ b/giflib-4.1.6/doc/gif89.txt @@ -0,0 +1,2475 @@ + + + Cover Sheet for the GIF89a Specification + + + DEFERRED CLEAR CODE IN LZW COMPRESSION + + There has been confusion about where clear codes can be found in the + data stream. As the specification says, they may appear at anytime. There + is not a requirement to send a clear code when the string table is full. + + It is the encoder's decision as to when the table should be cleared. When + the table is full, the encoder can chose to use the table as is, making no + changes to it until the encoder chooses to clear it. The encoder during + this time sends out codes that are of the maximum Code Size. + + As we can see from the above, when the decoder's table is full, it must + not change the table until a clear code is received. The Code Size is that + of the maximum Code Size. Processing other than this is done normally. + + Because of a large base of decoders that do not handle the decompression in + this manner, we ask developers of GIF encoding software to NOT implement + this feature until at least January 1991 and later if they see that their + particular market is not ready for it. This will give developers of GIF + decoding software time to implement this feature and to get it into the + hands of their clients before the decoders start "breaking" on the new + GIF's. It is not required that encoders change their software to take + advantage of the deferred clear code, but it is for decoders. + + APPLICATION EXTENSION BLOCK - APPLICATION IDENTIFIER + + There will be a Courtesy Directory file located on CompuServe in the PICS + forum. This directory will contain Application Identifiers for Application + Extension Blocks that have been used by developers of GIF applications. + This file is intended to help keep developers that wish to create + Application Extension Blocks from using the same Application Identifiers. + This is not an official directory; it is for voluntary participation only + and does not guarantee that someone will not use the same identifier. + + E-Mail can be sent to Larry Wood (forum manager of PICS) indicating the + request for inclusion in this file with an identifier. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + GRAPHICS INTERCHANGE FORMAT(sm) + + Version 89a + + (c)1987,1988,1989,1990 + + Copyright + CompuServe Incorporated + Columbus, Ohio + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +CompuServe Incorporated Graphics Interchange Format +Document Date : 31 July 1990 Programming Reference + + + + + + + + + + + Table of Contents + +Disclaimer................................................................. 1 + +Foreword................................................................... 1 + +Licensing.................................................................. 1 + +About the Document......................................................... 2 + +General Description........................................................ 2 + +Version Numbers............................................................ 2 + +The Encoder................................................................ 3 + +The Decoder................................................................ 3 + +Compliance................................................................. 3 + +About Recommendations...................................................... 4 + +About Color Tables......................................................... 4 + +Blocks, Extensions and Scope............................................... 4 + +Block Sizes................................................................ 5 + +Using GIF as an embedded protocol.......................................... 5 + +Data Sub-blocks............................................................ 5 + +Block Terminator........................................................... 6 + +Header..................................................................... 7 + +Logical Screen Descriptor.................................................. 8 + +Global Color Table......................................................... 10 + +Image Descriptor........................................................... 11 + +Local Color Table.......................................................... 13 + +Table Based Image Data..................................................... 14 + +Graphic Control Extension.................................................. 15 + +Comment Extension.......................................................... 17 + +Plain Text Extension....................................................... 18 + +Application Extension...................................................... 21 + +Trailer.................................................................... 23 + + + + + + + + + + + +Quick Reference Table...................................................... 24 + +GIF Grammar................................................................ 25 + +Glossary................................................................... 27 + +Conventions................................................................ 28 + +Interlaced Images.......................................................... 29 + +Variable-Length-Code LZW Compression....................................... 30 + +On-line Capabilities Dialogue.............................................. 33 + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + 1 + + +1. Disclaimer. + +The information provided herein is subject to change without notice. In no +event will CompuServe Incorporated be liable for damages, including any loss of +revenue, loss of profits or other incidental or consequential damages arising +out of the use or inability to use the information; CompuServe Incorporated +makes no claim as to the suitability of the information. + + +2. Foreword. + +This document defines the Graphics Interchange Format(sm). The specification +given here defines version 89a, which is an extension of version 87a. + +The Graphics Interchange Format(sm) as specified here should be considered +complete; any deviation from it should be considered invalid, including but not +limited to, the use of reserved or undefined fields within control or data +blocks, the inclusion of extraneous data within or between blocks, the use of +methods or algorithms not specifically listed as part of the format, etc. In +general, any and all deviations, extensions or modifications not specified in +this document should be considered to be in violation of the format and should +be avoided. + + +3. Licensing. + +The Graphics Interchange Format(c) is the copyright property of CompuServe +Incorporated. Only CompuServe Incorporated is authorized to define, redefine, +enhance, alter, modify or change in any way the definition of the format. + +CompuServe Incorporated hereby grants a limited, non-exclusive, royalty-free +license for the use of the Graphics Interchange Format(sm) in computer +software; computer software utilizing GIF(sm) must acknowledge ownership of the +Graphics Interchange Format and its Service Mark by CompuServe Incorporated, in +User and Technical Documentation. Computer software utilizing GIF, which is +distributed or may be distributed without User or Technical Documentation must +display to the screen or printer a message acknowledging ownership of the +Graphics Interchange Format and the Service Mark by CompuServe Incorporated; in +this case, the acknowledgement may be displayed in an opening screen or leading +banner, or a closing screen or trailing banner. A message such as the following +may be used: + + "The Graphics Interchange Format(c) is the Copyright property of + CompuServe Incorporated. GIF(sm) is a Service Mark property of + CompuServe Incorporated." + +For further information, please contact : + + CompuServe Incorporated + Graphics Technology Department + 5000 Arlington Center Boulevard + Columbus, Ohio 43220 + U. S. A. + +CompuServe Incorporated maintains a mailing list with all those individuals and +organizations who wish to receive copies of this document when it is corrected + + + + + + + + 2 + + +or revised. This service is offered free of charge; please provide us with your +mailing address. + + +4. About the Document. + +This document describes in detail the definition of the Graphics Interchange +Format. This document is intended as a programming reference; it is +recommended that the entire document be read carefully before programming, +because of the interdependence of the various parts. There is an individual +section for each of the Format blocks. Within each section, the sub-section +labeled Required Version refers to the version number that an encoder will have +to use if the corresponding block is used in the Data Stream. Within each +section, a diagram describes the individual fields in the block; the diagrams +are drawn vertically; top bytes in the diagram appear first in the Data Stream. +Bits within a byte are drawn most significant on the left end. Multi-byte +numeric fields are ordered Least Significant Byte first. Numeric constants are +represented as Hexadecimal numbers, preceded by "0x". Bit fields within a byte +are described in order from most significant bits to least significant bits. + + +5. General Description. + +The Graphics Interchange Format(sm) defines a protocol intended for the on-line +transmission and interchange of raster graphic data in a way that is +independent of the hardware used in their creation or display. + +The Graphics Interchange Format is defined in terms of blocks and sub-blocks +which contain relevant parameters and data used in the reproduction of a +graphic. A GIF Data Stream is a sequence of protocol blocks and sub-blocks +representing a collection of graphics. In general, the graphics in a Data +Stream are assumed to be related to some degree, and to share some control +information; it is recommended that encoders attempt to group together related +graphics in order to minimize hardware changes during processing and to +minimize control information overhead. For the same reason, unrelated graphics +or graphics which require resetting hardware parameters should be encoded +separately to the extent possible. + +A Data Stream may originate locally, as when read from a file, or it may +originate remotely, as when transmitted over a data communications line. The +Format is defined with the assumption that an error-free Transport Level +Protocol is used for communications; the Format makes no provisions for +error-detection and error-correction. + +The GIF Data Stream must be interpreted in context, that is, the application +program must rely on information external to the Data Stream to invoke the +decoder process. + + +6. Version Numbers. + +The version number in the Header of a Data Stream is intended to identify the +minimum set of capabilities required of a decoder in order to fully process the +Data Stream. An encoder should use the earliest possible version number that +includes all the blocks used in the Data Stream. Within each block section in +this document, there is an entry labeled Required Version which specifies the + + + + + + + + 3 + + +earliest version number that includes the corresponding block. The encoder +should make every attempt to use the earliest version number covering all the +blocks in the Data Stream; the unnecessary use of later version numbers will +hinder processing by some decoders. + + +7. The Encoder. + +The Encoder is the program used to create a GIF Data Stream. From raster data +and other information, the encoder produces the necessary control and data +blocks needed for reproducing the original graphics. + +The encoder has the following primary responsibilities. + + - Include in the Data Stream all the necessary information to + reproduce the graphics. + + - Insure that a Data Stream is labeled with the earliest possible + Version Number that will cover the definition of all the blocks in + it; this is to ensure that the largest number of decoders can + process the Data Stream. + + - Ensure encoding of the graphics in such a way that the decoding + process is optimized. Avoid redundant information as much as + possible. + + - To the extent possible, avoid grouping graphics which might + require resetting hardware parameters during the decoding process. + + - Set to zero (off) each of the bits of each and every field + designated as reserved. Note that some fields in the Logical Screen + Descriptor and the Image Descriptor were reserved under Version + 87a, but are used under version 89a. + + +8. The Decoder. + +The Decoder is the program used to process a GIF Data Stream. It processes the +Data Stream sequentially, parsing the various blocks and sub-blocks, using the +control information to set hardware and process parameters and interpreting the +data to render the graphics. + +The decoder has the following primary responsibilities. + + - Process each graphic in the Data Stream in sequence, without + delays other than those specified in the control information. + + - Set its hardware parameters to fit, as closely as possible, the + control information contained in the Data Stream. + + +9. Compliance. + +An encoder or a decoder is said to comply with a given version of the Graphics +Interchange Format if and only if it fully conforms with and correctly +implements the definition of the standard associated with that version. An + + + + + + + + 4 + + +encoder or a decoder may be compliant with a given version number and not +compliant with some subsequent version. + + +10. About Recommendations. + +Each block section in this document contains an entry labeled Recommendation; +this section lists a set of recommendations intended to guide and organize the +use of the particular blocks. Such recommendations are geared towards making +the functions of encoders and decoders more efficient, as well as making +optimal use of the communications bandwidth. It is advised that these +recommendations be followed. + + +11. About Color Tables. + +The GIF format utilizes color tables to render raster-based graphics. A color +table can have one of two different scopes: global or local. A Global Color +Table is used by all those graphics in the Data Stream which do not have a +Local Color Table associated with them. The scope of the Global Color Table is +the entire Data Stream. A Local Color Table is always associated with the +graphic that immediately follows it; the scope of a Local Color Table is +limited to that single graphic. A Local Color Table supersedes a Global Color +Table, that is, if a Data Stream contains a Global Color Table, and an image +has a Local Color Table associated with it, the decoder must save the Global +Color Table, use the Local Color Table to render the image, and then restore +the Global Color Table. Both types of color tables are optional, making it +possible for a Data Stream to contain numerous graphics without a color table +at all. For this reason, it is recommended that the decoder save the last +Global Color Table used until another Global Color Table is encountered. In +this way, a Data Stream which does not contain either a Global Color Table or +a Local Color Table may be processed using the last Global Color Table saved. +If a Global Color Table from a previous Stream is used, that table becomes the +Global Color Table of the present Stream. This is intended to reduce the +overhead incurred by color tables. In particular, it is recommended that an +encoder use only one Global Color Table if all the images in related Data +Streams can be rendered with the same table. If no color table is available at +all, the decoder is free to use a system color table or a table of its own. In +that case, the decoder may use a color table with as many colors as its +hardware is able to support; it is recommended that such a table have black and +white as its first two entries, so that monochrome images can be rendered +adequately. + +The Definition of the GIF Format allows for a Data Stream to contain only the +Header, the Logical Screen Descriptor, a Global Color Table and the GIF +Trailer. Such a Data Stream would be used to load a decoder with a Global Color +Table, in preparation for subsequent Data Streams without a color table at all. + + +12. Blocks, Extensions and Scope. + +Blocks can be classified into three groups : Control, Graphic-Rendering and +Special Purpose. Control blocks, such as the Header, the Logical Screen +Descriptor, the Graphic Control Extension and the Trailer, contain information +used to control the process of the Data Stream or information used in setting +hardware parameters. Graphic-Rendering blocks such as the Image Descriptor and + + + + + + + + 5 + + +the Plain Text Extension contain information and data used to render a graphic +on the display device. Special Purpose blocks such as the Comment Extension and +the Application Extension are neither used to control the process of the Data +Stream nor do they contain information or data used to render a graphic on the +display device. With the exception of the Logical Screen Descriptor and the +Global Color Table, whose scope is the entire Data Stream, all other Control +blocks have a limited scope, restricted to the Graphic-Rendering block that +follows them. Special Purpose blocks do not delimit the scope of any Control +blocks; Special Purpose blocks are transparent to the decoding process. +Graphic-Rendering blocks and extensions are used as scope delimiters for +Control blocks and extensions. The labels used to identify labeled blocks fall +into three ranges : 0x00-0x7F (0-127) are the Graphic Rendering blocks, +excluding the Trailer (0x3B); 0x80-0xF9 (128-249) are the Control blocks; +0xFA-0xFF (250-255) are the Special Purpose blocks. These ranges are defined so +that decoders can handle block scope by appropriately identifying block labels, +even when the block itself cannot be processed. + + +13. Block Sizes. + +The Block Size field in a block, counts the number of bytes remaining in the +block, not counting the Block Size field itself, and not counting the Block +Terminator, if one is to follow. Blocks other than Data Blocks are intended to +be of fixed length; the Block Size field is provided in order to facilitate +skipping them, not to allow their size to change in the future. Data blocks +and sub-blocks are of variable length to accommodate the amount of data. + + +14. Using GIF as an embedded protocol. + +As an embedded protocol, GIF may be part of larger application protocols, +within which GIF is used to render graphics. In such a case, the application +protocol could define a block within which the GIF Data Stream would be +contained. The application program would then invoke a GIF decoder upon +encountering a block of type GIF. This approach is recommended in favor of +using Application Extensions, which become overhead for all other applications +that do not process them. Because a GIF Data Stream must be processed in +context, the application must rely on some means of identifying the GIF Data +Stream outside of the Stream itself. + + +15. Data Sub-blocks. + + a. Description. Data Sub-blocks are units containing data. They do not + have a label, these blocks are processed in the context of control + blocks, wherever data blocks are specified in the format. The first byte + of the Data sub-block indicates the number of data bytes to follow. A + data sub-block may contain from 0 to 255 data bytes. The size of the + block does not account for the size byte itself, therefore, the empty + sub-block is one whose size field contains 0x00. + + b. Required Version. 87a. + + + + + + + + + + + + 6 + + + c. Syntax. + + 7 6 5 4 3 2 1 0 Field Name Type + +---------------+ + 0 | | Block Size Byte + +---------------+ + 1 | | + +- -+ + 2 | | + +- -+ + 3 | | + +- -+ + | | Data Values Byte + +- -+ + up | | + +- . . . . -+ + to | | + +- -+ + | | + +- -+ +255 | | + +---------------+ + + i) Block Size - Number of bytes in the Data Sub-block; the size + must be within 0 and 255 bytes, inclusive. + + ii) Data Values - Any 8-bit value. There must be exactly as many + Data Values as specified by the Block Size field. + + d. Extensions and Scope. This type of block always occurs as part of a + larger unit. It does not have a scope of itself. + + e. Recommendation. None. + + +16. Block Terminator. + + a. Description. This zero-length Data Sub-block is used to terminate a + sequence of Data Sub-blocks. It contains a single byte in the position of + the Block Size field and does not contain data. + + b. Required Version. 87a. + + c. Syntax. + + 7 6 5 4 3 2 1 0 Field Name Type + +---------------+ + 0 | | Block Size Byte + +---------------+ + + i) Block Size - Number of bytes in the Data Sub-block; this field + contains the fixed value 0x00. + + ii) Data Values - This block does not contain any data. + + + + + + + + + + 7 + + + d. Extensions and Scope. This block terminates the immediately preceding + sequence of Data Sub-blocks. This block cannot be modified by any + extension. + + e. Recommendation. None. + + +17. Header. + + a. Description. The Header identifies the GIF Data Stream in context. The + Signature field marks the beginning of the Data Stream, and the Version + field identifies the set of capabilities required of a decoder to fully + process the Data Stream. This block is REQUIRED; exactly one Header must + be present per Data Stream. + + b. Required Version. Not applicable. This block is not subject to a + version number. This block must appear at the beginning of every Data + Stream. + + c. Syntax. + + + 7 6 5 4 3 2 1 0 Field Name Type + +---------------+ + 0 | | Signature 3 Bytes + +- -+ + 1 | | + +- -+ + 2 | | + +---------------+ + 3 | | Version 3 Bytes + +- -+ + 4 | | + +- -+ + 5 | | + +---------------+ + + i) Signature - Identifies the GIF Data Stream. This field contains + the fixed value 'GIF'. + + ii) Version - Version number used to format the data stream. + Identifies the minimum set of capabilities necessary to a decoder + to fully process the contents of the Data Stream. + + Version Numbers as of 10 July 1990 : "87a" - May 1987 + "89a" - July 1989 + + Version numbers are ordered numerically increasing on the first two + digits starting with 87 (87,88,...,99,00,...,85,86) and + alphabetically increasing on the third character (a,...,z). + + iii) Extensions and Scope. The scope of this block is the entire + Data Stream. This block cannot be modified by any extension. + + + + + + + + + + + 8 + + + d. Recommendations. + + i) Signature - This field identifies the beginning of the GIF Data + Stream; it is not intended to provide a unique signature for the + identification of the data. It is recommended that the GIF Data + Stream be identified externally by the application. (Refer to + Appendix G for on-line identification of the GIF Data Stream.) + + ii) Version - ENCODER : An encoder should use the earliest possible + version number that defines all the blocks used in the Data Stream. + When two or more Data Streams are combined, the latest of the + individual version numbers should be used for the resulting Data + Stream. DECODER : A decoder should attempt to process the data + stream to the best of its ability; if it encounters a version + number which it is not capable of processing fully, it should + nevertheless, attempt to process the data stream to the best of its + ability, perhaps after warning the user that the data may be + incomplete. + + +18. Logical Screen Descriptor. + + a. Description. The Logical Screen Descriptor contains the parameters + necessary to define the area of the display device within which the + images will be rendered. The coordinates in this block are given with + respect to the top-left corner of the virtual screen; they do not + necessarily refer to absolute coordinates on the display device. This + implies that they could refer to window coordinates in a window-based + environment or printer coordinates when a printer is used. + + This block is REQUIRED; exactly one Logical Screen Descriptor must be + present per Data Stream. + + b. Required Version. Not applicable. This block is not subject to a + version number. This block must appear immediately after the Header. + + c. Syntax. + + 7 6 5 4 3 2 1 0 Field Name Type + +---------------+ + 0 | | Logical Screen Width Unsigned + +- -+ + 1 | | + +---------------+ + 2 | | Logical Screen Height Unsigned + +- -+ + 3 | | + +---------------+ + 4 | | | | | <Packed Fields> See below + +---------------+ + 5 | | Background Color Index Byte + +---------------+ + 6 | | Pixel Aspect Ratio Byte + +---------------+ + + + + + + + + + + 9 + + + <Packed Fields> = Global Color Table Flag 1 Bit + Color Resolution 3 Bits + Sort Flag 1 Bit + Size of Global Color Table 3 Bits + + i) Logical Screen Width - Width, in pixels, of the Logical Screen + where the images will be rendered in the displaying device. + + ii) Logical Screen Height - Height, in pixels, of the Logical + Screen where the images will be rendered in the displaying device. + + iii) Global Color Table Flag - Flag indicating the presence of a + Global Color Table; if the flag is set, the Global Color Table will + immediately follow the Logical Screen Descriptor. This flag also + selects the interpretation of the Background Color Index; if the + flag is set, the value of the Background Color Index field should + be used as the table index of the background color. (This field is + the most significant bit of the byte.) + + Values : 0 - No Global Color Table follows, the Background + Color Index field is meaningless. + 1 - A Global Color Table will immediately follow, the + Background Color Index field is meaningful. + + iv) Color Resolution - Number of bits per primary color available + to the original image, minus 1. This value represents the size of + the entire palette from which the colors in the graphic were + selected, not the number of colors actually used in the graphic. + For example, if the value in this field is 3, then the palette of + the original image had 4 bits per primary color available to create + the image. This value should be set to indicate the richness of + the original palette, even if not every color from the whole + palette is available on the source machine. + + v) Sort Flag - Indicates whether the Global Color Table is sorted. + If the flag is set, the Global Color Table is sorted, in order of + decreasing importance. Typically, the order would be decreasing + frequency, with most frequent color first. This assists a decoder, + with fewer available colors, in choosing the best subset of colors; + the decoder may use an initial segment of the table to render the + graphic. + + Values : 0 - Not ordered. + 1 - Ordered by decreasing importance, most + important color first. + + vi) Size of Global Color Table - If the Global Color Table Flag is + set to 1, the value in this field is used to calculate the number + of bytes contained in the Global Color Table. To determine that + actual size of the color table, raise 2 to [the value of the field + + 1]. Even if there is no Global Color Table specified, set this + field according to the above formula so that decoders can choose + the best graphics mode to display the stream in. (This field is + made up of the 3 least significant bits of the byte.) + + vii) Background Color Index - Index into the Global Color Table for + + + + + + + + 10 + + + the Background Color. The Background Color is the color used for + those pixels on the screen that are not covered by an image. If the + Global Color Table Flag is set to (zero), this field should be zero + and should be ignored. + + viii) Pixel Aspect Ratio - Factor used to compute an approximation + of the aspect ratio of the pixel in the original image. If the + value of the field is not 0, this approximation of the aspect ratio + is computed based on the formula: + + Aspect Ratio = (Pixel Aspect Ratio + 15) / 64 + + The Pixel Aspect Ratio is defined to be the quotient of the pixel's + width over its height. The value range in this field allows + specification of the widest pixel of 4:1 to the tallest pixel of + 1:4 in increments of 1/64th. + + Values : 0 - No aspect ratio information is given. + 1..255 - Value used in the computation. + + d. Extensions and Scope. The scope of this block is the entire Data + Stream. This block cannot be modified by any extension. + + e. Recommendations. None. + + +19. Global Color Table. + + a. Description. This block contains a color table, which is a sequence of + bytes representing red-green-blue color triplets. The Global Color Table + is used by images without a Local Color Table and by Plain Text + Extensions. Its presence is marked by the Global Color Table Flag being + set to 1 in the Logical Screen Descriptor; if present, it immediately + follows the Logical Screen Descriptor and contains a number of bytes + equal to + 3 x 2^(Size of Global Color Table+1). + + This block is OPTIONAL; at most one Global Color Table may be present + per Data Stream. + + b. Required Version. 87a + + + + + + + + + + + + + + + + + + + + + + + 11 + + + c. Syntax. + + 7 6 5 4 3 2 1 0 Field Name Type + +===============+ + 0 | | Red 0 Byte + +- -+ + 1 | | Green 0 Byte + +- -+ + 2 | | Blue 0 Byte + +- -+ + 3 | | Red 1 Byte + +- -+ + | | Green 1 Byte + +- -+ + up | | + +- . . . . -+ ... + to | | + +- -+ + | | Green 255 Byte + +- -+ +767 | | Blue 255 Byte + +===============+ + + + d. Extensions and Scope. The scope of this block is the entire Data + Stream. This block cannot be modified by any extension. + + e. Recommendation. None. + + +20. Image Descriptor. + + a. Description. Each image in the Data Stream is composed of an Image + Descriptor, an optional Local Color Table, and the image data. Each + image must fit within the boundaries of the Logical Screen, as defined + in the Logical Screen Descriptor. + + The Image Descriptor contains the parameters necessary to process a table + based image. The coordinates given in this block refer to coordinates + within the Logical Screen, and are given in pixels. This block is a + Graphic-Rendering Block, optionally preceded by one or more Control + blocks such as the Graphic Control Extension, and may be optionally + followed by a Local Color Table; the Image Descriptor is always followed + by the image data. + + This block is REQUIRED for an image. Exactly one Image Descriptor must + be present per image in the Data Stream. An unlimited number of images + may be present per Data Stream. + + b. Required Version. 87a. + + + + + + + + + + + + + + 12 + + + c. Syntax. + + 7 6 5 4 3 2 1 0 Field Name Type + +---------------+ + 0 | | Image Separator Byte + +---------------+ + 1 | | Image Left Position Unsigned + +- -+ + 2 | | + +---------------+ + 3 | | Image Top Position Unsigned + +- -+ + 4 | | + +---------------+ + 5 | | Image Width Unsigned + +- -+ + 6 | | + +---------------+ + 7 | | Image Height Unsigned + +- -+ + 8 | | + +---------------+ + 9 | | | | | | <Packed Fields> See below + +---------------+ + + <Packed Fields> = Local Color Table Flag 1 Bit + Interlace Flag 1 Bit + Sort Flag 1 Bit + Reserved 2 Bits + Size of Local Color Table 3 Bits + + i) Image Separator - Identifies the beginning of an Image + Descriptor. This field contains the fixed value 0x2C. + + ii) Image Left Position - Column number, in pixels, of the left edge + of the image, with respect to the left edge of the Logical Screen. + Leftmost column of the Logical Screen is 0. + + iii) Image Top Position - Row number, in pixels, of the top edge of + the image with respect to the top edge of the Logical Screen. Top + row of the Logical Screen is 0. + + iv) Image Width - Width of the image in pixels. + + v) Image Height - Height of the image in pixels. + + vi) Local Color Table Flag - Indicates the presence of a Local Color + Table immediately following this Image Descriptor. (This field is + the most significant bit of the byte.) + + + Values : 0 - Local Color Table is not present. Use + Global Color Table if available. + 1 - Local Color Table present, and to follow + immediately after this Image Descriptor. + + + + + + + + + 13 + + + vii) Interlace Flag - Indicates if the image is interlaced. An image + is interlaced in a four-pass interlace pattern; see Appendix E for + details. + + Values : 0 - Image is not interlaced. + 1 - Image is interlaced. + + viii) Sort Flag - Indicates whether the Local Color Table is + sorted. If the flag is set, the Local Color Table is sorted, in + order of decreasing importance. Typically, the order would be + decreasing frequency, with most frequent color first. This assists + a decoder, with fewer available colors, in choosing the best subset + of colors; the decoder may use an initial segment of the table to + render the graphic. + + Values : 0 - Not ordered. + 1 - Ordered by decreasing importance, most + important color first. + + ix) Size of Local Color Table - If the Local Color Table Flag is + set to 1, the value in this field is used to calculate the number + of bytes contained in the Local Color Table. To determine that + actual size of the color table, raise 2 to the value of the field + + 1. This value should be 0 if there is no Local Color Table + specified. (This field is made up of the 3 least significant bits + of the byte.) + + d. Extensions and Scope. The scope of this block is the Table-based Image + Data Block that follows it. This block may be modified by the Graphic + Control Extension. + + e. Recommendation. None. + + +21. Local Color Table. + + a. Description. This block contains a color table, which is a sequence of + bytes representing red-green-blue color triplets. The Local Color Table + is used by the image that immediately follows. Its presence is marked by + the Local Color Table Flag being set to 1 in the Image Descriptor; if + present, the Local Color Table immediately follows the Image Descriptor + and contains a number of bytes equal to + 3x2^(Size of Local Color Table+1). + If present, this color table temporarily becomes the active color table + and the following image should be processed using it. This block is + OPTIONAL; at most one Local Color Table may be present per Image + Descriptor and its scope is the single image associated with the Image + Descriptor that precedes it. + + b. Required Version. 87a. + + + + + + + + + + + + + + 14 + + + c. Syntax. + + 7 6 5 4 3 2 1 0 Field Name Type + +===============+ + 0 | | Red 0 Byte + +- -+ + 1 | | Green 0 Byte + +- -+ + 2 | | Blue 0 Byte + +- -+ + 3 | | Red 1 Byte + +- -+ + | | Green 1 Byte + +- -+ + up | | + +- . . . . -+ ... + to | | + +- -+ + | | Green 255 Byte + +- -+ +767 | | Blue 255 Byte + +===============+ + + + d. Extensions and Scope. The scope of this block is the Table-based Image + Data Block that immediately follows it. This block cannot be modified by + any extension. + + e. Recommendations. None. + + +22. Table Based Image Data. + + a. Description. The image data for a table based image consists of a + sequence of sub-blocks, of size at most 255 bytes each, containing an + index into the active color table, for each pixel in the image. Pixel + indices are in order of left to right and from top to bottom. Each index + must be within the range of the size of the active color table, starting + at 0. The sequence of indices is encoded using the LZW Algorithm with + variable-length code, as described in Appendix F + + b. Required Version. 87a. + + c. Syntax. The image data format is as follows: + + 7 6 5 4 3 2 1 0 Field Name Type + +---------------+ + | | LZW Minimum Code Size Byte + +---------------+ + + +===============+ + | | + / / Image Data Data Sub-blocks + | | + +===============+ + + + + + + + + + 15 + + + i) LZW Minimum Code Size. This byte determines the initial number + of bits used for LZW codes in the image data, as described in + Appendix F. + + d. Extensions and Scope. This block has no scope, it contains raster + data. Extensions intended to modify a Table-based image must appear + before the corresponding Image Descriptor. + + e. Recommendations. None. + + +23. Graphic Control Extension. + + a. Description. The Graphic Control Extension contains parameters used + when processing a graphic rendering block. The scope of this extension is + the first graphic rendering block to follow. The extension contains only + one data sub-block. + + This block is OPTIONAL; at most one Graphic Control Extension may precede + a graphic rendering block. This is the only limit to the number of + Graphic Control Extensions that may be contained in a Data Stream. + + b. Required Version. 89a. + + c. Syntax. + + 7 6 5 4 3 2 1 0 Field Name Type + +---------------+ + 0 | | Extension Introducer Byte + +---------------+ + 1 | | Graphic Control Label Byte + +---------------+ + + +---------------+ + 0 | | Block Size Byte + +---------------+ + 1 | | | | | <Packed Fields> See below + +---------------+ + 2 | | Delay Time Unsigned + +- -+ + 3 | | + +---------------+ + 4 | | Transparent Color Index Byte + +---------------+ + + +---------------+ + 0 | | Block Terminator Byte + +---------------+ + + + <Packed Fields> = Reserved 3 Bits + Disposal Method 3 Bits + User Input Flag 1 Bit + Transparent Color Flag 1 Bit + + i) Extension Introducer - Identifies the beginning of an extension + + + + + + + + 16 + + + block. This field contains the fixed value 0x21. + + ii) Graphic Control Label - Identifies the current block as a + Graphic Control Extension. This field contains the fixed value + 0xF9. + + iii) Block Size - Number of bytes in the block, after the Block + Size field and up to but not including the Block Terminator. This + field contains the fixed value 4. + + iv) Disposal Method - Indicates the way in which the graphic is to + be treated after being displayed. + + Values : 0 - No disposal specified. The decoder is + not required to take any action. + 1 - Do not dispose. The graphic is to be left + in place. + 2 - Restore to background color. The area used by the + graphic must be restored to the background color. + 3 - Restore to previous. The decoder is required to + restore the area overwritten by the graphic with + what was there prior to rendering the graphic. + 4-7 - To be defined. + + v) User Input Flag - Indicates whether or not user input is + expected before continuing. If the flag is set, processing will + continue when user input is entered. The nature of the User input + is determined by the application (Carriage Return, Mouse Button + Click, etc.). + + Values : 0 - User input is not expected. + 1 - User input is expected. + + When a Delay Time is used and the User Input Flag is set, + processing will continue when user input is received or when the + delay time expires, whichever occurs first. + + vi) Transparency Flag - Indicates whether a transparency index is + given in the Transparent Index field. (This field is the least + significant bit of the byte.) + + Values : 0 - Transparent Index is not given. + 1 - Transparent Index is given. + + vii) Delay Time - If not 0, this field specifies the number of + hundredths (1/100) of a second to wait before continuing with the + processing of the Data Stream. The clock starts ticking immediately + after the graphic is rendered. This field may be used in + conjunction with the User Input Flag field. + + viii) Transparency Index - The Transparency Index is such that when + encountered, the corresponding pixel of the display device is not + modified and processing goes on to the next pixel. The index is + present if and only if the Transparency Flag is set to 1. + + ix) Block Terminator - This zero-length data block marks the end of + + + + + + + + 17 + + the Graphic Control Extension. + + d. Extensions and Scope. The scope of this Extension is the graphic + rendering block that follows it; it is possible for other extensions to + be present between this block and its target. This block can modify the + Image Descriptor Block and the Plain Text Extension. + + e. Recommendations. + + i) Disposal Method - The mode Restore To Previous is intended to be + used in small sections of the graphic; the use of this mode imposes + severe demands on the decoder to store the section of the graphic + that needs to be saved. For this reason, this mode should be used + sparingly. This mode is not intended to save an entire graphic or + large areas of a graphic; when this is the case, the encoder should + make every attempt to make the sections of the graphic to be + restored be separate graphics in the data stream. In the case where + a decoder is not capable of saving an area of a graphic marked as + Restore To Previous, it is recommended that a decoder restore to + the background color. + + ii) User Input Flag - When the flag is set, indicating that user + input is expected, the decoder may sound the bell (0x07) to alert + the user that input is being expected. In the absence of a + specified Delay Time, the decoder should wait for user input + indefinitely. It is recommended that the encoder not set the User + Input Flag without a Delay Time specified. + + +24. Comment Extension. + + a. Description. The Comment Extension contains textual information which + is not part of the actual graphics in the GIF Data Stream. It is suitable + for including comments about the graphics, credits, descriptions or any + other type of non-control and non-graphic data. The Comment Extension + may be ignored by the decoder, or it may be saved for later processing; + under no circumstances should a Comment Extension disrupt or interfere + with the processing of the Data Stream. + + This block is OPTIONAL; any number of them may appear in the Data Stream. + + b. Required Version. 89a. + + + + + + + + + + + + + + + + + + + + + + + 18 + + + c. Syntax. + + 7 6 5 4 3 2 1 0 Field Name Type + +---------------+ + 0 | | Extension Introducer Byte + +---------------+ + 1 | | Comment Label Byte + +---------------+ + + +===============+ + | | + N | | Comment Data Data Sub-blocks + | | + +===============+ + + +---------------+ + 0 | | Block Terminator Byte + +---------------+ + + i) Extension Introducer - Identifies the beginning of an extension + block. This field contains the fixed value 0x21. + + ii) Comment Label - Identifies the block as a Comment Extension. + This field contains the fixed value 0xFE. + + iii) Comment Data - Sequence of sub-blocks, each of size at most + 255 bytes and at least 1 byte, with the size in a byte preceding + the data. The end of the sequence is marked by the Block + Terminator. + + iv) Block Terminator - This zero-length data block marks the end of + the Comment Extension. + + d. Extensions and Scope. This block does not have scope. This block + cannot be modified by any extension. + + e. Recommendations. + + i) Data - This block is intended for humans. It should contain + text using the 7-bit ASCII character set. This block should + not be used to store control information for custom processing. + + ii) Position - This block may appear at any point in the Data + Stream at which a block can begin; however, it is recommended that + Comment Extensions do not interfere with Control or Data blocks; + they should be located at the beginning or at the end of the Data + Stream to the extent possible. + + +25. Plain Text Extension. + + a. Description. The Plain Text Extension contains textual data and the + parameters necessary to render that data as a graphic, in a simple form. + The textual data will be encoded with the 7-bit printable ASCII + characters. Text data are rendered using a grid of character cells + + + + + + + + + 19 + + + defined by the parameters in the block fields. Each character is rendered + in an individual cell. The textual data in this block is to be rendered + as mono-spaced characters, one character per cell, with a best fitting + font and size. For further information, see the section on + Recommendations below. The data characters are taken sequentially from + the data portion of the block and rendered within a cell, starting with + the upper left cell in the grid and proceeding from left to right and + from top to bottom. Text data is rendered until the end of data is + reached or the character grid is filled. The Character Grid contains an + integral number of cells; in the case that the cell dimensions do not + allow for an integral number, fractional cells must be discarded; an + encoder must be careful to specify the grid dimensions accurately so that + this does not happen. This block requires a Global Color Table to be + available; the colors used by this block reference the Global Color Table + in the Stream if there is one, or the Global Color Table from a previous + Stream, if one was saved. This block is a graphic rendering block, + therefore it may be modified by a Graphic Control Extension. This block + is OPTIONAL; any number of them may appear in the Data Stream. + + b. Required Version. 89a. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + 20 + + + c. Syntax. + + 7 6 5 4 3 2 1 0 Field Name Type + +---------------+ + 0 | | Extension Introducer Byte + +---------------+ + 1 | | Plain Text Label Byte + +---------------+ + + +---------------+ + 0 | | Block Size Byte + +---------------+ + 1 | | Text Grid Left Position Unsigned + +- -+ + 2 | | + +---------------+ + 3 | | Text Grid Top Position Unsigned + +- -+ + 4 | | + +---------------+ + 5 | | Text Grid Width Unsigned + +- -+ + 6 | | + +---------------+ + 7 | | Text Grid Height Unsigned + +- -+ + 8 | | + +---------------+ + 9 | | Character Cell Width Byte + +---------------+ + 10 | | Character Cell Height Byte + +---------------+ + 11 | | Text Foreground Color Index Byte + +---------------+ + 12 | | Text Background Color Index Byte + +---------------+ + + +===============+ + | | + N | | Plain Text Data Data Sub-blocks + | | + +===============+ + + +---------------+ + 0 | | Block Terminator Byte + +---------------+ + + i) Extension Introducer - Identifies the beginning of an extension + block. This field contains the fixed value 0x21. + + ii) Plain Text Label - Identifies the current block as a Plain Text + Extension. This field contains the fixed value 0x01. + + iii) Block Size - Number of bytes in the extension, after the Block + Size field and up to but not including the beginning of the data + portion. This field contains the fixed value 12. + + + + + + + + 21 + + + iv) Text Grid Left Position - Column number, in pixels, of the left + edge of the text grid, with respect to the left edge of the Logical + Screen. + + v) Text Grid Top Position - Row number, in pixels, of the top edge + of the text grid, with respect to the top edge of the Logical + Screen. + + vi) Image Grid Width - Width of the text grid in pixels. + + vii) Image Grid Height - Height of the text grid in pixels. + + viii) Character Cell Width - Width, in pixels, of each cell in the + grid. + + ix) Character Cell Height - Height, in pixels, of each cell in the + grid. + + x) Text Foreground Color Index - Index into the Global Color Table + to be used to render the text foreground. + + xi) Text Background Color Index - Index into the Global Color Table + to be used to render the text background. + + xii) Plain Text Data - Sequence of sub-blocks, each of size at most + 255 bytes and at least 1 byte, with the size in a byte preceding + the data. The end of the sequence is marked by the Block + Terminator. + + xiii) Block Terminator - This zero-length data block marks the end + of the Plain Text Data Blocks. + + d. Extensions and Scope. The scope of this block is the Plain Text Data + Block contained in it. This block may be modified by the Graphic Control + Extension. + + e. Recommendations. The data in the Plain Text Extension is assumed to be + preformatted. The selection of font and size is left to the discretion of + the decoder. If characters less than 0x20 or greater than 0xf7 are + encountered, it is recommended that the decoder display a Space character + (0x20). The encoder should use grid and cell dimensions such that an + integral number of cells fit in the grid both horizontally as well as + vertically. For broadest compatibility, character cell dimensions should + be around 8x8 or 8x16 (width x height); consider an image for unusual + sized text. + + +26. Application Extension. + + a. Description. The Application Extension contains application-specific + information; it conforms with the extension block syntax, as described + below, and its block label is 0xFF. + + b. Required Version. 89a. + + + + + + + + + + 22 + + + c. Syntax. + + 7 6 5 4 3 2 1 0 Field Name Type + +---------------+ + 0 | | Extension Introducer Byte + +---------------+ + 1 | | Extension Label Byte + +---------------+ + + +---------------+ + 0 | | Block Size Byte + +---------------+ + 1 | | + +- -+ + 2 | | + +- -+ + 3 | | Application Identifier 8 Bytes + +- -+ + 4 | | + +- -+ + 5 | | + +- -+ + 6 | | + +- -+ + 7 | | + +- -+ + 8 | | + +---------------+ + 9 | | + +- -+ + 10 | | Appl. Authentication Code 3 Bytes + +- -+ + 11 | | + +---------------+ + + +===============+ + | | + | | Application Data Data Sub-blocks + | | + | | + +===============+ + + +---------------+ + 0 | | Block Terminator Byte + +---------------+ + + i) Extension Introducer - Defines this block as an extension. This + field contains the fixed value 0x21. + + ii) Application Extension Label - Identifies the block as an + Application Extension. This field contains the fixed value 0xFF. + + iii) Block Size - Number of bytes in this extension block, + following the Block Size field, up to but not including the + beginning of the Application Data. This field contains the fixed + value 11. + + + + + + + + 23 + + + iv) Application Identifier - Sequence of eight printable ASCII + characters used to identify the application owning the Application + Extension. + + v) Application Authentication Code - Sequence of three bytes used + to authenticate the Application Identifier. An Application program + may use an algorithm to compute a binary code that uniquely + identifies it as the application owning the Application Extension. + + + d. Extensions and Scope. This block does not have scope. This block + cannot be modified by any extension. + + e. Recommendation. None. + + +27. Trailer. + + a. Description. This block is a single-field block indicating the end of + the GIF Data Stream. It contains the fixed value 0x3B. + + b. Required Version. 87a. + + c. Syntax. + + 7 6 5 4 3 2 1 0 Field Name Type + +---------------+ + 0 | | GIF Trailer Byte + +---------------+ + + d. Extensions and Scope. This block does not have scope, it terminates + the GIF Data Stream. This block may not be modified by any extension. + + e. Recommendations. None. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + 24 + + +Appendix +A. Quick Reference Table. + +Block Name Required Label Ext. Vers. +Application Extension Opt. (*) 0xFF (255) yes 89a +Comment Extension Opt. (*) 0xFE (254) yes 89a +Global Color Table Opt. (1) none no 87a +Graphic Control Extension Opt. (*) 0xF9 (249) yes 89a +Header Req. (1) none no N/A +Image Descriptor Opt. (*) 0x2C (044) no 87a (89a) +Local Color Table Opt. (*) none no 87a +Logical Screen Descriptor Req. (1) none no 87a (89a) +Plain Text Extension Opt. (*) 0x01 (001) yes 89a +Trailer Req. (1) 0x3B (059) no 87a + +Unlabeled Blocks +Header Req. (1) none no N/A +Logical Screen Descriptor Req. (1) none no 87a (89a) +Global Color Table Opt. (1) none no 87a +Local Color Table Opt. (*) none no 87a + +Graphic-Rendering Blocks +Plain Text Extension Opt. (*) 0x01 (001) yes 89a +Image Descriptor Opt. (*) 0x2C (044) no 87a (89a) + +Control Blocks +Graphic Control Extension Opt. (*) 0xF9 (249) yes 89a + +Special Purpose Blocks +Trailer Req. (1) 0x3B (059) no 87a +Comment Extension Opt. (*) 0xFE (254) yes 89a +Application Extension Opt. (*) 0xFF (255) yes 89a + +legend: (1) if present, at most one occurrence + (*) zero or more occurrences + (+) one or more occurrences + +Notes : The Header is not subject to Version Numbers. +(89a) The Logical Screen Descriptor and the Image Descriptor retained their +syntax from version 87a to version 89a, but some fields reserved under version +87a are used under version 89a. + + + + + + + + + + + + + + + + + + + + + + + 25 + + +Appendix +B. GIF Grammar. + +A Grammar is a form of notation to represent the sequence in which certain +objects form larger objects. A grammar is also used to represent the number of +objects that can occur at a given position. The grammar given here represents +the sequence of blocks that form the GIF Data Stream. A grammar is given by +listing its rules. Each rule consists of the left-hand side, followed by some +form of equals sign, followed by the right-hand side. In a rule, the +right-hand side describes how the left-hand side is defined. The right-hand +side consists of a sequence of entities, with the possible presence of special +symbols. The following legend defines the symbols used in this grammar for GIF. + +Legend: <> grammar word + ::= defines symbol + * zero or more occurrences + + one or more occurrences + | alternate element + [] optional element + +Example: + +<GIF Data Stream> ::= Header <Logical Screen> <Data>* Trailer + +This rule defines the entity <GIF Data Stream> as follows. It must begin with a +Header. The Header is followed by an entity called Logical Screen, which is +defined below by another rule. The Logical Screen is followed by the entity +Data, which is also defined below by another rule. Finally, the entity Data is +followed by the Trailer. Since there is no rule defining the Header or the +Trailer, this means that these blocks are defined in the document. The entity +Data has a special symbol (*) following it which means that, at this position, +the entity Data may be repeated any number of times, including 0 times. For +further reading on this subject, refer to a standard text on Programming +Languages. + + +The Grammar. + +<GIF Data Stream> ::= Header <Logical Screen> <Data>* Trailer + +<Logical Screen> ::= Logical Screen Descriptor [Global Color Table] + +<Data> ::= <Graphic Block> | + <Special-Purpose Block> + +<Graphic Block> ::= [Graphic Control Extension] <Graphic-Rendering Block> + +<Graphic-Rendering Block> ::= <Table-Based Image> | + Plain Text Extension + +<Table-Based Image> ::= Image Descriptor [Local Color Table] Image Data + +<Special-Purpose Block> ::= Application Extension | + Comment Extension + + + + + + + + + + 26 + + +NOTE : The grammar indicates that it is possible for a GIF Data Stream to +contain the Header, the Logical Screen Descriptor, a Global Color Table and the +GIF Trailer. This special case is used to load a GIF decoder with a Global +Color Table, in preparation for subsequent Data Streams without color tables at +all. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + 27 + + +Appendix +C. Glossary. + +Active Color Table - Color table used to render the next graphic. If the next +graphic is an image which has a Local Color Table associated with it, the +active color table becomes the Local Color Table associated with that image. +If the next graphic is an image without a Local Color Table, or a Plain Text +Extension, the active color table is the Global Color Table associated with the +Data Stream, if there is one; if there is no Global Color Table in the Data +Stream, the active color table is a color table saved from a previous Data +Stream, or one supplied by the decoder. + +Block - Collection of bytes forming a protocol unit. In general, the term +includes labeled and unlabeled blocks, as well as Extensions. + +Data Stream - The GIF Data Stream is composed of blocks and sub-blocks +representing images and graphics, together with control information to render +them on a display device. All control and data blocks in the Data Stream must +follow the Header and must precede the Trailer. + +Decoder - A program capable of processing a GIF Data Stream to render the +images and graphics contained in it. + +Encoder - A program capable of capturing and formatting image and graphic +raster data, following the definitions of the Graphics Interchange Format. + +Extension - A protocol block labeled by the Extension Introducer 0x21. + +Extension Introducer - Label (0x21) defining an Extension. + +Graphic - Data which can be rendered on the screen by virtue of some algorithm. +The term graphic is more general than the term image; in addition to images, +the term graphic also includes data such as text, which is rendered using +character bit-maps. + +Image - Data representing a picture or a drawing; an image is represented by an +array of pixels called the raster of the image. + +Raster - Array of pixel values representing an image. + + + + + + + + + + + + + + + + + + + + + + + + + 28 + + +Appendix +D. Conventions. + +Animation - The Graphics Interchange Format is not intended as a platform for +animation, even though it can be done in a limited way. + +Byte Ordering - Unless otherwise stated, multi-byte numeric fields are ordered +with the Least Significant Byte first. + +Color Indices - Color indices always refer to the active color table, either +the Global Color Table or the Local Color Table. + +Color Order - Unless otherwise stated, all triple-component RGB color values +are specified in Red-Green-Blue order. + +Color Tables - Both color tables, the Global and the Local, are optional; if +present, the Global Color Table is to be used with every image in the Data +Stream for which a Local Color Table is not given; if present, a Local Color +Table overrides the Global Color Table. However, if neither color table is +present, the application program is free to use an arbitrary color table. If +the graphics in several Data Streams are related and all use the same color +table, an encoder could place the color table as the Global Color Table in the +first Data Stream and leave subsequent Data Streams without a Global Color +Table or any Local Color Tables; in this way, the overhead for the table is +eliminated. It is recommended that the decoder save the previous Global Color +Table to be used with the Data Stream that follows, in case it does not contain +either a Global Color Table or any Local Color Tables. In general, this allows +the application program to use past color tables, significantly reducing +transmission overhead. + +Extension Blocks - Extensions are defined using the Extension Introducer code +to mark the beginning of the block, followed by a block label, identifying the +type of extension. Extension Codes are numbers in the range from 0x00 to 0xFF, +inclusive. Special purpose extensions are transparent to the decoder and may be +omitted when transmitting the Data Stream on-line. The GIF capabilities +dialogue makes the provision for the receiver to request the transmission of +all blocks; the default state in this regard is no transmission of Special +purpose blocks. + +Reserved Fields - All Reserved Fields are expected to have each bit set to zero +(off). + + + + + + + + + + + + + + + + + + + + + + + 29 + + +Appendix +E. Interlaced Images. + +The rows of an Interlaced images are arranged in the following order: + + Group 1 : Every 8th. row, starting with row 0. (Pass 1) + Group 2 : Every 8th. row, starting with row 4. (Pass 2) + Group 3 : Every 4th. row, starting with row 2. (Pass 3) + Group 4 : Every 2nd. row, starting with row 1. (Pass 4) + +The Following example illustrates how the rows of an interlaced image are +ordered. + + Row Number Interlace Pass + + 0 ----------------------------------------- 1 + 1 ----------------------------------------- 4 + 2 ----------------------------------------- 3 + 3 ----------------------------------------- 4 + 4 ----------------------------------------- 2 + 5 ----------------------------------------- 4 + 6 ----------------------------------------- 3 + 7 ----------------------------------------- 4 + 8 ----------------------------------------- 1 + 9 ----------------------------------------- 4 + 10 ----------------------------------------- 3 + 11 ----------------------------------------- 4 + 12 ----------------------------------------- 2 + 13 ----------------------------------------- 4 + 14 ----------------------------------------- 3 + 15 ----------------------------------------- 4 + 16 ----------------------------------------- 1 + 17 ----------------------------------------- 4 + 18 ----------------------------------------- 3 + 19 ----------------------------------------- 4 + + + + + + + + + + + + + + + + + + + + + + + + + + + + + 30 + + +Appendix +F. Variable-Length-Code LZW Compression. + +The Variable-Length-Code LZW Compression is a variation of the Lempel-Ziv +Compression algorithm in which variable-length codes are used to replace +patterns detected in the original data. The algorithm uses a code or +translation table constructed from the patterns encountered in the original +data; each new pattern is entered into the table and its index is used to +replace it in the compressed stream. + +The compressor takes the data from the input stream and builds a code or +translation table with the patterns as it encounters them; each new pattern is +entered into the code table and its index is added to the output stream; when a +pattern is encountered which had been detected since the last code table +refresh, its index from the code table is put on the output stream, thus +achieving the data compression. The expander takes input from the compressed +data stream and builds the code or translation table from it; as the compressed +data stream is processed, codes are used to index into the code table and the +corresponding data is put on the decompressed output stream, thus achieving +data decompression. The details of the algorithm are explained below. The +Variable-Length-Code aspect of the algorithm is based on an initial code size +(LZW-initial code size), which specifies the initial number of bits used for +the compression codes. When the number of patterns detected by the compressor +in the input stream exceeds the number of patterns encodable with the current +number of bits, the number of bits per LZW code is increased by one. + +The Raster Data stream that represents the actual output image can be +represented as: + + 7 6 5 4 3 2 1 0 + +---------------+ + | LZW code size | + +---------------+ + + +---------------+ ----+ + | block size | | + +---------------+ | + | | +-- Repeated as many + | data bytes | | times as necessary. + | | | + +---------------+ ----+ + + . . . . . . ------- The code that terminates the LZW + compressed data must appear before + Block Terminator. + +---------------+ + |0 0 0 0 0 0 0 0| Block Terminator + +---------------+ + +The conversion of the image from a series of pixel values to a transmitted or +stored character stream involves several steps. In brief these steps are: + +1. Establish the Code Size - Define the number of bits needed to represent the +actual data. + +2. Compress the Data - Compress the series of image pixels to a series of + + + + + + + + 31 + + +compression codes. + +3. Build a Series of Bytes - Take the set of compression codes and convert to a +string of 8-bit bytes. + +4. Package the Bytes - Package sets of bytes into blocks preceded by character +counts and output. + +ESTABLISH CODE SIZE + +The first byte of the Compressed Data stream is a value indicating the minimum +number of bits required to represent the set of actual pixel values. Normally +this will be the same as the number of color bits. Because of some algorithmic +constraints however, black & white images which have one color bit must be +indicated as having a code size of 2. +This code size value also implies that the compression codes must start out one +bit longer. + +COMPRESSION + +The LZW algorithm converts a series of data values into a series of codes which +may be raw values or a code designating a series of values. Using text +characters as an analogy, the output code consists of a character or a code +representing a string of characters. + +The LZW algorithm used in GIF matches algorithmically with the standard LZW +algorithm with the following differences: + +1. A special Clear code is defined which resets all compression/decompression +parameters and tables to a start-up state. The value of this code is 2**<code +size>. For example if the code size indicated was 4 (image was 4 bits/pixel) +the Clear code value would be 16 (10000 binary). The Clear code can appear at +any point in the image data stream and therefore requires the LZW algorithm to +process succeeding codes as if a new data stream was starting. Encoders should +output a Clear code as the first code of each image data stream. + +2. An End of Information code is defined that explicitly indicates the end of +the image data stream. LZW processing terminates when this code is encountered. +It must be the last code output by the encoder for an image. The value of this +code is <Clear code>+1. + +3. The first available compression code value is <Clear code>+2. + +4. The output codes are of variable length, starting at <code size>+1 bits per +code, up to 12 bits per code. This defines a maximum code value of 4095 +(0xFFF). Whenever the LZW code value would exceed the current code length, the +code length is increased by one. The packing/unpacking of these codes must then +be altered to reflect the new code length. + +BUILD 8-BIT BYTES + +Because the LZW compression used for GIF creates a series of variable length +codes, of between 3 and 12 bits each, these codes must be reformed into a +series of 8-bit bytes that will be the characters actually stored or +transmitted. This provides additional compression of the image. The codes are +formed into a stream of bits as if they were packed right to left and then + + + + + + + + 32 + + +picked off 8 bits at a time to be output. + +Assuming a character array of 8 bits per character and using 5 bit codes to be +packed, an example layout would be similar to: + + + +---------------+ + 0 | | bbbaaaaa + +---------------+ + 1 | | dcccccbb + +---------------+ + 2 | | eeeedddd + +---------------+ + 3 | | ggfffffe + +---------------+ + 4 | | hhhhhggg + +---------------+ + . . . + +---------------+ + N | | + +---------------+ + + +Note that the physical packing arrangement will change as the number of bits +per compression code change but the concept remains the same. + +PACKAGE THE BYTES + +Once the bytes have been created, they are grouped into blocks for output by +preceding each block of 0 to 255 bytes with a character count byte. A block +with a zero byte count terminates the Raster Data stream for a given image. +These blocks are what are actually output for the GIF image. This block format +has the side effect of allowing a decoding program the ability to read past the +actual image data if necessary by reading block counts and then skipping over +the data. + + + +FURTHER READING + +[1] Ziv, J. and Lempel, A. : "A Universal Algorithm for Sequential Data +Compression", IEEE Transactions on Information Theory, May 1977. +[2] Welch, T. : "A Technique for High-Performance Data Compression", Computer, +June 1984. +[3] Nelson, M.R. : "LZW Data Compression", Dr. Dobb's Journal, October 1989. + + + + + + + + + + + + + + + + + + + 33 + + +Appendix +G. On-line Capabilities Dialogue. + +NOTE : This section is currently (10 July 1990) under revision; the information +provided here should be used as general guidelines. Code written based on this +information should be designed in a flexible way to accommodate any changes +resulting from the revisions. + +The following sequences are defined for use in mediating control between a GIF +sender and GIF receiver over an interactive communications line. These +sequences do not apply to applications that involve downloading of static GIF +files and are not considered part of a GIF file. + +GIF CAPABILITIES ENQUIRY + +The GIF Capabilities Enquiry sequence is issued from a host and requests an +interactive GIF decoder to return a response message that defines the graphics +parameters for the decoder. This involves returning information about available +screen sizes, number of bits/color supported and the amount of color detail +supported. The escape sequence for the GIF Capabilities Enquiry is defined as: + +ESC[>0g 0x1B 0x5B 0x3E 0x30 0x67 + +GIF CAPABILITIES RESPONSE + +The GIF Capabilities Response message is returned by an interactive GIF decoder +and defines the decoder's display capabilities for all graphics modes that are +supported by the software. Note that this can also include graphics printers as +well as a monitor screen. The general format of this message is: + +#version;protocol{;dev, width, height, color-bits, color-res}...<CR> + + +'#' GIF Capabilities Response identifier character. +version GIF format version number; initially '87a'. +protocol='0' No end-to-end protocol supported by decoder Transfer as direct + 8-bit data stream. +protocol='1' Can use CIS B+ error correction protocol to transfer GIF data + interactively from the host directly to the display. +dev = '0' Screen parameter set follows. +dev = '1' Printer parameter set follows. +width Maximum supported display width in pixels. +height Maximum supported display height in pixels. +color-bits Number of bits per pixel supported. The number of supported + colors is therefore 2**color-bits. +color-res Number of bits per color component supported in the hardware + color palette. If color-res is '0' then no hardware palette + table is available. + +Note that all values in the GIF Capabilities Response are returned as ASCII +decimal numbers and the message is terminated by a Carriage Return character. + +The following GIF Capabilities Response message describes three standard IBM PC +Enhanced Graphics Adapter configurations with no printer; the GIF data stream + + + + + + + + + + 34 + + +can be processed within an error correcting protocol: + +#87a;1;0,320,200,4,0;0,640,200,2,2;0,640,350,4,2<CR> + +ENTER GIF GRAPHICS MODE + +Two sequences are currently defined to invoke an interactive GIF decoder into +action. The only difference between them is that different output media are +selected. These sequences are: + +ESC[>1g Display GIF image on screen + + 0x1B 0x5B 0x3E 0x31 0x67 + +ESC[>2g Display image directly to an attached graphics printer. The image may +optionally be displayed on the screen as well. + + 0x1B 0x5B 0x3E 0x32 0x67 + +Note that the 'g' character terminating each sequence is in lowercase. + +INTERACTIVE ENVIRONMENT + +The assumed environment for the transmission of GIF image data from an +interactive application is a full 8-bit data stream from host to micro. All +256 character codes must be transferrable. The establishing of an 8-bit data +path for communications will normally be taken care of by the host application +programs. It is however up to the receiving communications programs supporting +GIF to be able to receive and pass on all 256 8-bit codes to the GIF decoder +software. + + diff --git a/giflib-4.1.6/doc/gif_lib.html b/giflib-4.1.6/doc/gif_lib.html new file mode 100644 index 0000000..df2ada4 --- /dev/null +++ b/giflib-4.1.6/doc/gif_lib.html @@ -0,0 +1,713 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gif_lib</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>The GIFLIB Library</H1></CENTER> + +<CENTER><BLOCKQUOTE> +Gershon Elber, May 1991<BR> +Eric S. Raymond, Sep 1992<BR> +Toshio Kuratomi, May 2004<br> +</BLOCKQUOTE></CENTER> + +The Graphics Interchange Format(c) is the Copyright property of +CompuServe Incorporated. GIF(sm) is a Service Mark property of CompuServe +Incorporated.<P> + +Gershon wrote: "This library was written because I couldn't find +anything similar and I wanted one. I was inspired by the RLE Utah tool kit, +which I hoped to port to an IBM PC, but found it to be too machine specific, +and its compression ratio too low. I compromised on the GIF format, but I am +not sure how long 8 bits per pixel will be enough."<P> + +This document explains the GIF library code in directory `lib'. The +code is collected into libgif.a which is used in all the utilities in +`util'. It can be used in any application needs to read/write the GIF +file format. This document does </em>not</em> explain the GIF file +format and assumes you know it, at least to the level of the GIF file +structure.<P> + +When a GIF file is opened, a GIF file descriptor is created which +is a pointer to GifFileType structure as follows:<P> + +<pre><code> +typedef struct GifFileType { + int SWidth, SHeight, /* Screen dimensions. */ + SColorResolution, /* How many colors can we generate? */ + SBackGroundColor; /* I hope you understand this one... */ + ColorMapObject *SColorMap; /* NULL if not exists. */ + int ImageCount; /* Number of current image */ + GifImageDesc Image; /* Block describing current image */ + struct SavedImage *SavedImages; /* Use this to accumulate file state */ + VoidPtr Private; /* The regular user should not mess with this one! */ +} GifFileType; +</code></pre> + +This structure was copied from gif_lib.h - the header file for the GIF +library. Any application program that uses the libgif.a library should +include it. Members beginning with S refer to GIF Screen; others hold +properties of the current image (a GIF file may have more than one image) +or point to allocated store used by various routines.<P> + +The user almost never writes into this structure (exception: it may +occasionally useful to alter things in the SavedImages array), but can read +any of these items at any time it is valid (image information is invalid +until first image was read/write).<P> + +As the library needs to keep its own internal data, a Private pointer +to hidden data is included. Applications should ignore this item.<P> + +The library has no static data. This means that it is fully reentrant +and any number of GIF files (up to memory limits) can be opened for +read/write. Instead of the static data, internal structure pointed by the +Private pointer is used.<P> + +The library allocates its own memory dynamically, on opening of files, +and releases that once closed. The user is never required to allocate +any memory for any of the functions of this library nor to free them +directly.<P> + +In order to reduce disk access, the file buffer is increased to +FILE_BUFFER_SIZE (defined in gif_lib.h). The library was compiled in large +model on the PC as the memory allocated per file is quite big: about 17k for +decoding (DGIF_LIB.C), and 32k for encoding (EGIF_LIB.C), excluding the +FILE_BUFFER_SIZE.<P> + +Here is a module summary:<P> + +<DL> +<DT>egif_lib.c <DD> Encoding routines, all prefixed with E.<P> + +<DT>dgif_lib.c <DD> Decoding routines, all prefixed with D.<P> + +<DT>dev2gif.c <DD> Routines to convert specific device buffers into GIF files.<P> + +<DT>gifalloc.c <DD> Routines for colormap handling and GIF record allocation.<P> + +<DT>gif_font.c <DD> The 8x8 font table for the GIF utility font.<P> + +<DT>gif_err.c <DD> Error handler for the library.<P> +</DL> + +The library includes a sixth file of hash-function code which is accessed +internally only.<P> + +<P>Most of the routines return GIF_ERROR (see gif_lib.h) if something +went wrong, GIF_OK otherwise. After an error return, the code in the +gif_err.c module can be used to do something about it.<P> + +In addition, a module to parse command line arguments is supplied. +This module is called getarg.c and its headers are in getarg.h. See the header +of getarg.c for details on its usage.<P> + +<H1>Decoding (dgif_lib.c)</H1> + +The following functions are used to set up input from a GIF:<P> + +<pre><code> +GifFileType *DGifOpenFileName(char *GifFileName) +</code></pre> + +Open a new GIF file using the given GifFileName, and read its Screen +information. +</code></pre> + +If any error occurs, NULL is returned and the error handler can be +used to get the exact error (see gif_err.c). +</code></pre> + +The file is opened in binary mode, and its buffer size is set to +FILE_BUFFER_SIZE bytes. +</code></pre> + +<pre><code> +GifFileType *DGifOpenFileHandle(int GifFileHandle) +</code></pre> + +Open a new GIF file using the given GifFileHandle, and read its Screen +information.<P> + +If any error occurs, NULL is returned and the error handler can be +used to get the exact error (see gif_err.c).<P> + +The file is opened in binary mode, and its buffer size is set to +FILE_BUFFER_SIZE bytes.<P> + +Once you have acquired a handle on a GIF, there are two ways to read it in. +The high-level function + +<pre><code> +int DGifSlurp(GifFileType) +</code></pre> + +reads the rest of a complete (possibly multi-image) GIF file from the +indicated file handle into in-core allocated structures. It returns +GIF_OK on success, GIF_ERROR on failure.<P> + +Once you have done this, all image, raster, and extension-block data in the +GIF is accessable in the SavedImages member (see the structures in fif_lib.h). +When you have modified the image to taste, write it out with EGifSpew().<P> + +If you are handling large images on a memory-limited machine, you may need +to use the following functions for sequential read.<P> + +<pre><code> +int DGifGetScreenDesc(GifFileType *GifFile) +</code></pre> + +Reads the screen information into the GifFile structure. Note this +routine is automatically called once a file is opened, and therefore +usually need not be called explicitly.<P> + +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.<P> + +<pre><code> +int DGifGetRecordType(GifFileType *GifFile, GifRecordType *GifType) +</code></pre> + +As the GIF file can have different records in arbitrary order, this +routine should be called once the file was open to detect the next +record type, and act upon it. It can return these types in GifType:<P> + +<DL> +<DT> 1. UndefinedRecordType <DD> something is wrong!<P> + +<DT> 2. ScreenDescRecordType <DD> screen information. As the screen info + is automatically read in when the file is open, this should + not happen.<P> + +<DT> 3. ImageDescRecordType <DD> next record is an image descriptor.<P> + +<DT> 4. ExtensionRecordType <DD> next record is extension block.<P> + +<DT> 5. TerminateRecordType <DD> last record reached, can close the file.<P> +</DL> +The first two types can usually be ignored. The function +returns GIF_ERROR if something went wrong, GIF_OK otherwise. + +<pre><code> +int DGifGetImageDesc(GifFileType *GifFile) +</code></pre> + +Reads image information into the GifFile structure. +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.<P> + +<pre><code><A NAME="DGifGetLine"> +int DGifGetLine(GifFileType *GifFile, PixelType *GifLine, int GifLineLen) +</A></code></pre> + +Load a block of pixels from the GIF file. The line can be +of any length. More than that, this routine may be interleaved with +DGifGetPixel until all pixels have been read.<P> + +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.</P> + +<pre><code> +int DGifGetPixel(GifFileType *GifFile, PixelType GifPixel) +</code></pre> + +Loads one pixel from the GIF file. This routine may be interleaved +with <a href="#DGifGetLine">DGifGetLine</a>, until all pixels are +read. Because of the overhead per each call, use of this routine is +not recommended.<P> + +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.<P> + +<pre><code> +int DGifGetComment(GifFileType *GifFile, char *GifComment) +</code></pre> + +Load a comment from the GIF file. Because DGifGetRecordType will +only tell if the record is of type extension, this routine should be +called iff it is known %100 that is must be a comment.<P> + +For the definition of a comment, see <a +href="#EGifPutComment">EGifPutComment</a>. Returns GIF_ERROR if +something went wrong, GIF_OK otherwise.<P> + +<pre><code> +int DGifGetExtension( + GifFileType *GifFile, + int *GifExtCode, + ByteType **GifExtension) +</code></pre> + +Loads an extension block from the GIF file. Extension blocks +are optional in GIF files. This routine should be followed by +<a href="#DGifGetExtensionNext">DGifGetExtensionNext</a>.<P> + +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.<P> + +<pre><code><A NAME="DGifGetExtensionNext"> +int DGifGetExtensionNext(GifFileType *GifFile, ByteType **GifExtension) +</A> </code></pre> + +As extensions may contain more than one block, use this routine to +continue after DGifGetExtension, until *GifExtension is NULL.<P> + +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.<P> + + +<pre><code> +int DGifGetCode( + GifFileType *GifFile, + int *GifCodeSize, ByteType **GifCodeBlock) +</code></pre> + +It sometimes may be desired to read the compressed code as is +without decoding it. This routine does exactly that (with +DGifGetCodeNext), and can be used instead of DGifGetLine.<P> + +This compressed code information can be written out using the +EGifPutCode/EGifPutCodeNext sequence (see gifpos.c for example). +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.<P> + +<pre><code> +int DGifGetCodeNext(GifFileType *GifFile, ByteType **GifCodeBlock) +</code></pre> + +See DGifGetCode above.<P> + +<pre><code> +int DGifGetLZCodes(GifFileType *GifFile, int *GifCode) +</code></pre> + +This routine can be called instead of DGifGetLine/DGifGetPixel or +DGifGetCode/DGifGetCodeNext to get the 12 bits LZ codes of the images. +It will be used mainly for debugging purposes (see GifText.c for +example).<P> + +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.<P> + +<pre><code> +int DGifCloseFile(GifFileType *GifFile) +</code></pre> + +Close GIF file and free all memory allocated for it. GifFile should +not be used after this routine has been called.<P> + +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.<P> + +<H1>Encoding (egif_lib.c)</H1> + +There are two ways to write out a GIF. The high-level function<P> + +<pre> +int EGifSpew(GifFileType *GifFile, int GifFileHandle) +</pre> + +Writes a complete (possibly multi-image) GIF file to the indicated file +handle from in-core allocated structures created by a previous DGifSlurp() +or equivalent operations. Its arguments are a GIF file descriptor (as +above) and an ordinary output file descriptor.<P> + +The file is written with a GIF87 stamp unless it contains one of the four +special extension blocks defined in GIF89, in which case it is written +with a GIF89 stamp.<P> + +If you are handling large images on a memory-limited machine, you may need +to use the following functions for sequential write.<P> + +<pre><code> +GifFileType *EGifOpenFileName(char *GifFileName, int GifTestExistance) +</code></pre> + +Open a new GIF file using the given GifFileName. If GifTestExistance +is TRUE, and file exists, the file is not destroyed, and NULL +returned.<P> + +If any error occurs, NULL is returned and the error handler can be +used to get the exact error (see gif_err.c).<P> + +The file is opened in binary mode, and its buffer size is set to +FILE_BUFFER_SIZE bytes.<P> + +<pre><code> +GifFileType *EGifOpenFileHandle(int GifFileHandle) +</code></pre> + +Open a new GIF file using the given GifFileHandle.<P> + +If any error occurs, NULL is returned and the error handler can be +used to get the exact error (see gif_err.c).<P> + +The file is opened in binary mode, and its buffer size is set to +FILE_BUFFER_SIZE bytes.<P> + +<pre><code> +void EGifSetGifVersion(char *Version) +</code></pre> + +Sets the GIF version of all files opened, until another call to this +routine is made. Version is a 3 characters string of the form "87a" +or "89a". No test is made to validate this string.<P> + +<pre><code> +int EGifPutScreenDesc(GifFileType *GifFile, + int GifWidth, int GifHeight, + int GifColorRes, int GifBackGround, + ColorMapObject *GifColorMap) +</code></pre> + +Update the GifFile Screen parameters, in GifFile structure and in +the real file. If error occurs, returns GIF_ERROR (see gif_lib.h), +otherwise GIF_OK.<P> + +This routine should be called immediately after the GIF file was +opened.<P> + +<pre><code> +int EGifPutImageDesc(GifFileType *GifFile, + int GifLeft, int GifTop, + int Width, int GifHeight, + int GifInterlace, + ColorMapObject *GifColorMap) +</code></pre> + +Update GifFile Image parameters, in GifFile structure and in the real +file. if error occurs returns GIF_ERROR (see gif_lib.h), otherwise +GIF_OK.<P> + +This routine should be called each time a new image must be +dumped to the file.<P> + +<pre><code><A NAME="EGifPutLine"> +int EGifPutLine(GifFileType *GifFile, PixelType *GifLine, int GifLineLen) +</A> </code></pre> + +Dumps a block of pixels out to the GIF file. The slab can be +of any length. More than that, this routine may be interleaved with +<a href="#EGifPutPixel"></a>, until all pixels have been sent.<P> + +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.<P> + +<pre><code><A NAME="EGifPutPixel"> +int EGifPutPixel(GifFileType *GifFile, PixelType GifPixel) +</A></code></pre> + +Dumps one pixel to the GIF file. This routine may be interleaved with +<a href="#EGifPutLine">EGifPutLine</a>, until all pixels were sent. +Because of the overhead for each call, use of this routine is not +recommended.<P> + +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.<P> + +<pre><code><A NAME="EGifPutComment"> +int EGifPutComment(GifFileType *GifFile, char *GifComment) +</A></code></pre> + +Uses extension GIF records to save a string as a comment is the file. +The extension code is 'C' (for Comment).<P> + +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.<P> + +<pre><code> +int EGifPutExtension( + GifFileType *GifFile, + int GifExtCode, + int GifExtLen, + void *GifExtension) +</code></pre> + +Dumps the given extension block into the GIF file. Extension blocks +are optional in GIF file. Extension blocks of more than 255 bytes or +more than one block are not supported in this function. Please use +EGifPutExtensionFirst, EGifPutExtensionNext, and EGifPutExtensionLast +if your extension blocks may fall into this category.<P> + +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.<P> + +<pre><code> +int EGifPutExtensionFirst( + GifFileType * GifFile, + int GifExtCode, + int GifExtLen, + const VoidPtr GifExtension) +</code></pre> +Dumps the beginning of a GIF extension block to a GIF file. Extension blocks +are optional in GIF files. This function outputs the meta information +necessary to a GIF extension block and the extension data described in the +GifExtension argument.<P> + +Further blocks of the GIF Extension should be dumped using +EGifPutExtensionNext. When finished with this extension block, +EGifPutExtensionLast should be called to output the block termination.<P> + +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.<P> + +<pre><code> +int EGifPutExtensionNext( + GifFileType * GifFile, + int GifExtCode, + int GifExtLen, + const VoidPtr GifExtension) +</code></pre> +Dumps a subblock of a GIF extension to a GIF File. Extension blocks are +optional in GIF files. This function will write the Extension Data in +GifExtension to the file as a subblock of the preceding Extension Block. +Repeat calling of this function until all data subblocks have been output.<P> + +Note that EGifPutExtensionFirst needs to be called before any calls to this +function. EGifPutExtensionLast should be called to finish the Extension +block after all data subblocks have been output.<P> + +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.<P> + +<pre><code> +int EGifPutExtensionLast( + GifFileType * GifFile, + int GifExtCode, + int GifExtLen, + const VoidPtr GifExtension) +</code></pre> +Dumps an optional GIF extension data subblock and the GIF extension block +terminator to a GIF File. Extension blocks are optional in GIF files. This +function will write the Extension Data in GifExtension to the file as a +subblock of the preceding Extension Block. Then it will output the GIF +extension block terminator to end the current Extension block. As a special +case, if GifExtLen is zero, the function will assume there isn't another +data block to output and will simply write the block terminator.<P> + +Note that a call to EGifPutExtensionFirst is needed to open the GIF +Extension Block prior to calling this function.<P> + +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.<P> + +<pre><code> +int EGifPutCode( + GifFileType *GifFile, + int *GifCodeSize, + ByteType **GifCodeBlock) +</code></pre> + +It sometimes may be desired to write the compressed code as is +without decoding it. For example a filter for a GIF file that change +only screen size (GifPos), does not need the exact pixel values. +Piping out the compressed image as is makes this process much +faster.<P> + +This routine does exactly that (with EGifPutCodeNext), and can be +used instead of EGifPutLine. You'll usually use this with the +DGifGetCode/DgifGetCodeNext routines, which reads the compressed +code, while EGifPutCode/EGifPutCodeNext write it out. See gifpos.c +for example.<P> + +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.<P> + +<pre><code> +int EGifPutCodeNext(GifFileType *GifFile, ByteType **GifCodeBlock) +</code></pre> + +See EGifPutCode above.<P> + +<pre><code> +int EGifCloseFile(GifFileType *GifFile) +</code></pre> + +Close a GIF file and free all memory allocated for it. gif-file$ +should not be used, once this routine was called.<P> + +Returns GIF_ERROR if something went wrong, GIF_OK otherwise.<P> + +<H1>Color map handling and allocation routines</H1> + +<pre><code> +ColorMapObject *MakeMapObject(int ColorCount, GifColorType *ColorMap) +</code></pre> + +Allocate storage for a color map object with the given number of +RGB triplet slots. If the second argument is non-NULL, initialize +the color table portion of the new map from it. Returns NULL if +memory is exhausted or if the size is not a power of 2 <= 256.<P> + +<pre><code> +void FreeMapObject(ColorMapObject *Object) +</code></pre> + +Free the storage occupied by a ColorMapObject that is no longer needed.<P> + +<pre><code> +ColorMapObject *UnionColorMap( + ColorMapObject *ColorIn1, ColorMapObject *ColorIn2, + GifPixelType ColorTransIn2[]) +</code></pre> + +Create the union of two given color maps and return it. If the result +won't fit into 256 colors, NULL is returned, the allocated union +otherwise. ColorIn1 is copied as it to ColorUnion, while colors from +ColorIn2 are copied iff they didn't exist before. ColorTransIn2 maps +the old ColorIn2 into ColorUnion color map table.<P> + +<pre><code> +SavedImage *GifAttachImage(GifFileType *GifFile) +</code></pre> + +Add an image block to the SavedImages array. The image block is +initially zeroed out. This image block will be seen by any following +EGifSpew() calls. +</code></pre> + +<H1>The GIF Utility Font</H1> + +The 8x8 utility font used in text2gif and gifcolor lives in the library +module gif_font.c, in a table called AsciiTable. The library header file +includes suitable externs and defines.<P> + +The GIF utility font support includes entry points for drawing legends +on in-core images, drawing boxes and rectangles, and boxing text. +These entry points are as follows:<P> + +<pre><code> +void DrawText( + SavedImage *Image, + const int x, const int y, + const char *legend, + const int color) +</code></pre> + +Draw text using the 8x8 utility font on the saved image. Upper left +corner of the text is at image pixel (x, y). Use the specified +color index.<P> + +<pre><code> +void DrawBox(SavedImage *Image, + const int x, const int y, + const int w, const int h, + const int color) +</code></pre> + +Draw a box on the saved image. Upper left corner of the box is at +image pixels (x, y), width is w, height is h. Use the specified color +index.<P> + +<pre><code> +void DrawRectangle(SavedImage *Image, + const int x, const int y, + const int w, const int h, + const int color) +</code></pre> + +Draw a (filled) rectangle on the saved image. Upper left corner of +the box is at image pixels (x, y), width is w, height is h. Use the +specified color index.<P> + +<pre><code> +void DrawBoxedText(SavedImage *Image, + const int x, const int y, + const char *legend, + const int border, + const int bg, const int fg) +</code></pre> + +Draw text on a filled rectangle. The rectangle will be sized to fit +the text, with upper left hand corner at (x, y) on the saved image. +The `border' argument specifies a pixel margin around the text. The +`bg' argument is the color table index to fill the rectangle with; +`fg' is the color table index to draw the text with.<P> + +This function interprets some characters in the legend string +specially. A tab (\t) is interpreted as a command to center the +following text in the box. A carriage return (\r) is interpreted +as a request for a line break.<P> + +<H1>Error Handling (egif_lib.c)</H1> + +<pre><code> +void PrintGifError(void) +</code></pre> + +Print a one-line diagnostic on the last giflib error to stderr.<P> + +<pre><code> +int GifLastError(void) +</code></pre> + +Return the number of the last giflib error, and clear the error. +The error types are defined in gif_lib.h.<P> + +Note it is the user's responsibility to call the file closing +routine, so the file will be closed (if was opened), and allocated +memory will be released.<P> + +<H1>Device Specific (XXX2gif.c)</H1> + +<pre><code> +int DumpScreen2Gif(char *FileName, int ReqGraphDriver, int ReqGraphMode1, + int ReqGraphMode2) +</code></pre> + +Dumps the whole device buffer as specified by GraphDriver and +GraphMode (as defined in TC 2.0 graphics.h) into FileName as GIF file. +Current devices supported:<P> + +<pre> + 1. Hercules. + + 2. EGA, EGA64, EGAMONO (all modes - see TC graphics.h). + + 3. VGA (all modes - see TC graphics.h). + + 4. SVGA_SPECIAL. This mode is special and not supported by Borland + graphics.h. ReqGraphDriver must be equal to 999, and ReqGraphMode + is ignored. This modes assumes 800 by 600 in 16 colors. + Returns GIF_ERROR if something went wrong, GIF_OK otherwise. + + 5. SGI 4D using gl graphic library - window dump. + + 6. X11 window dump. +</pre> + + +<H1>Command Line Parsing</H1> + +<pre><code> +int GAGetArgs(int argc, char **argv, char *CtrlStr, ...) +</code></pre> + +Main routine of this module. Given argc & argv as received by +the main procedure, the command line CtrlStr, and the addresses of +all parameters, parse the command line, and update the parameters.<P> + +The CtrlStr defines what types of variables should follow. Look at the +beginning of getarg.c for exact usage.<P> + +Returns 0 if successful, error number (as defined by getarg.h) otherwise.<P> + +<pre><code> +void GAPrintErrMsg(int Error) +</code></pre> + +If an error occurred in GAGetARgs, this routine may be used to print +one line diagnostic to stderr.<P> + +<pre><code> +void GAPrintHowTo(char *CtrlStr) +</code></pre> + +Given the same CtrlStr as for GAGetArgs, can be used to print a one line +'how to use'. <P> + +<H1>Skeletons of GIF filters</H1> + +If you are developing on a virtual-memory OS such as most flavors of +UNIX, or are otherwise sure of having enough memory to keep all of GIFs you +need to operate in core, writing a filter is trivial. See the file +gifspnge.c in util.<P> + +A sequential filter skeleton will usually look like the example file +giffiltr.c in util.<P> + +<P>Please look at the utilities in the util directory for more ideas once +you feel comfortable with these skeletons. Also try to follow the coding +standards of this package if you want the maintainer to officially add your new +utility to it.<P> + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifasm.html b/giflib-4.1.6/doc/gifasm.html new file mode 100644 index 0000000..ae28751 --- /dev/null +++ b/giflib-4.1.6/doc/gifasm.html @@ -0,0 +1,59 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifasm</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifasm</H1></CENTER> + +A program to assemble multiple GIF files into one, or disassemble a single GIF +file with multiple images into single image files.<P> + +<H1>Usage:</H1> + +<pre> +gifasm [-q] [-a] [-d OutFileName] [-h] gif-file... +</pre> + +If no gif-file is given, GifAsm will try to read a GIF file from stdin, if +in disassembly mode only (-d).<P> + +<H1>Memory required:</H1> + +Line. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-a] +<DD> Assemble. This is the default, and the GifFile(s) are assembled to + stdout. Note the screen descriptor (including screen color map) is taken + from the first file, while other screen descriptors are ignored. + As this tool requires at least 2 GIF files as input, no attempt will be + made to read stdin if none specified on command line.<P> + +<DT> [-d OutFileName] +<DD> Disassemble GifFile (if specified on command line) or + stdin, into several files of the form OutFileNameXX, where XX are two + decimal digits. Obviously up to 100 files can be generated this way. + Note: in this mode nothing is sent to stdout.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifbg.html b/giflib-4.1.6/doc/gifbg.html new file mode 100644 index 0000000..4f107c3 --- /dev/null +++ b/giflib-4.1.6/doc/gifbg.html @@ -0,0 +1,86 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifbg</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifbg</H1></CENTER> + +A program to generate a single-color test pattern GIF with gradually changing +intensity in any of the basic 8 directions.<P> + +<H1>Usage:</H1> + +<pre> +gifbg [-q] [-d Dir] [-l #Lvls] [-c R G B] [-m MinI] [-M MaxI] [-s W H] [-h] +</pre> + +The gifbg program reads no input, and will dump the created GIF file +to stdout.<P> + +<H1>Memory required:</H1> + +Line. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-d Dir] +<DD> Select direction the intensity of the background should increase. + Direction can be one of the 8 principal directions:<P> + +<pre> + "T" - for Top "TR" - for Top Right + "R" - for Right "BR" - for Bottom Right + "B" - for Bottom "BL" - for Bottom Left + "L" - for left "TL" - for Top Left +</pre> + + The compass directions may be use as synonyms for the above directions, so + for example "NE" is equal to "TR".<P> + + Direction is case insensitive. The default direction is Top (North).<P> + +<DT> [-l #Lvls] +<DD> Number of levels the color will be scaled to. Default is 16.<P> + +<DT> [-c R G B] +<DD> What to use as the primary background color to scale. + This color is scaled between the minimum intensity (MinI) and maximum + intensity (MaxI) from one end of the screen to the other as defined by Dir. + See below (-m & -M) for MinI & MaxI. Default is Blue (0, 0, 255).<P> + +<DT> [-m MinI] +<DD> Minimum intensity (in percent) to scale color. Default 10%<P> + +<DT> [-M MaxI] +<DD> Maximum intensity (in percent) to scale color. Default 100%<P> + +<DT> [-s W H] +<DD> Size of image to create. Default 640 by 350.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Notes:</H1> + +If MinI == MaxI = 100 (%) and #Lvls == 2 then boolean mask image of specified +size will be created - all foreground. This can be used as a square mask for +the <a href="gifcomb.html"></a>gifcomb utility.<P> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifburst.html b/giflib-4.1.6/doc/gifburst.html new file mode 100644 index 0000000..3088b36 --- /dev/null +++ b/giflib-4.1.6/doc/gifburst.html @@ -0,0 +1,48 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifburst</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifburst</H1></CENTER> + +The gifburst program takes a named GIF file and breaks it into equal-sized +tiles. This is useful if a GIF is too large for your viewer, so you have +to look at it in sections.<P> + +<H1>Usage:</H1> + +<pre> +gifburst [-s n] [-p b] gif-file +</pre> + +<H1>Memory required:</H1> + +Proportional to the size of the largest pasted image. + +<H1>Options:</H1> + +<DT> [-s nnn] +<DD> Specify the number of pieces. Valid values are presently 4 (2x2) + and 6 (2x3). Default is 4. + +<DT> [-p nnn] +<DD> Specify the number of pixels of overlap between interior boundaries + of pieces. Default 20. + +<H1>Note:</H1> + +The gifburst program is written on Perl, using the C utilities. You must have +both the giflib utilities and Perl installed to run it.<P> + +<H1>Author:</H1> + +Eric S. Raymond <esr@snark.thyrsus.com><P> + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifclip.html b/giflib-4.1.6/doc/gifclip.html new file mode 100644 index 0000000..9710b4f --- /dev/null +++ b/giflib-4.1.6/doc/gifclip.html @@ -0,0 +1,75 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifclip</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifclip</H1></CENTER> + +A program to clip images in GIF files. Only one image in a GIF file can be +modified at a time. Neither the image position on screen nor the screen size +is modified (use <a href="gifpos.html">gifpos</a> for that).<P> + +<H1>Usage:</H1> + +<pre> +gifclip [-q] [-i Xmin Ymin Xmax Ymax] [-n n Xmin Ymin Xmax Ymax] [-c] [-h] gif-file +</pre> + +If no gif-file is given, GifClip will try to read a GIF file from stdin.<P> + +<H1>Memory required:</H1> + +Line. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Default off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-i Xmin Ymin Xmax Ymax] +<DD> Clip first image to the dimensions as specified + by the 4 coordinates (Xmin Ymin Xmax Ymax) of a box clipping region.<P> + + For example: '-i 11 22 33 44' will crop the box from top left [11,22] + to bottom right [33,44] out of the first image.<P> + + If the first parameter is bigger than third one (Xmin > Xmax) they are + swapped. Same for Y.<P> + + The dimensions of the clipped image must be confined to original image + width and height. Note the clipped image includes both the min & max + boundary; an image of width W can have coordinates 0 to W-1 (zero based).<P> + + Only one of -i or -n can be specified.<P> + +<DT> [-n n Xmin Ymin Xmax Ymax] +<DD> Same as -i above but for the nth image: + `-n 1 11 22 33 44' is exactly the same as the example in -i. Only one of + -i or -n can be specified.<P> + +<DT> [-c] +<DD> Complement. This removes horizontal and/or vertical bands of the + image. For example `-c -i 638 3 658 13' would remove a horizontal band + 11 pixels deep beginning at raster line 3, and a vertical band 21 pixels + right beginning at pixel 658.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +Note: all coordinates are 0-based --- the top left corner is (0, 0).<P> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifclrmp.html b/giflib-4.1.6/doc/gifclrmp.html new file mode 100644 index 0000000..6ca3a9d --- /dev/null +++ b/giflib-4.1.6/doc/gifclrmp.html @@ -0,0 +1,77 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifclrmp</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifclrmp</H1></CENTER> + +A program to modify GIF image colormaps. Any local colormap in a GIF file can +be modified at a time, or the global screen one.<P> + +<H1>Usage:</H1> + +<pre> +gifclrmap [-q] [-s] [-t trans] [-l map] [-g Gamma] [-i image] [-h] gif-file +</pre> + +If no gif-file is given, GifClip will try to read a GIF file from stdin.<P> + +<H1>Memory required:</H1> + +Line. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-s] +<DD> Select the global screen color map.<P> + +<DT> [-l map] +<DD> Load color map from this file instead of selected color map.<P> + +<DT> [-t trans] +<DD> Change color index values. The change is made to both + the selected color table and the raster bits of the selected image. A + translation file is a list of pairs of `before' and `after' index values. + At present, the `before' index values must be in ascending order starting + from 0.<P> + +<DT> [-g Gamma] +<DD> Apply gamma correction to selected color map.<P> + +<DT>[-i image] +<DD> Select the color map of the numbered image.<P> + +<DT>[-h] +<DD> Print one command line help, similar to Usage above.<P> +</DL> + +<H1>Notes:</H1> + +<UL> +<LI> +The default operation is to dump out the selected color map in text +format.<P> + +<LI> +The file to load/dump is simply one color map entry per line. Each such +entry line has four integers: "ColorIndex Red Green Blue", where color +index is in ascending order starting from 1.<P> +</UL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifcolor.html b/giflib-4.1.6/doc/gifcolor.html new file mode 100644 index 0000000..8276070 --- /dev/null +++ b/giflib-4.1.6/doc/gifcolor.html @@ -0,0 +1,60 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifcolor</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifcolor</H1></CENTER> + +A program to generate color test patterns. Feed it a color map file (as +generated, say, by the -s otion of GifClrMp) and it will generate a GIF +containing lines of the form + +<pre> + Color %-3d: [%-3d, %-3d, %-3d]: +</pre> + +where the first number is the zero-based color index, and the triple is the +index's [Red, Green, Blue] value. There will be one such line for each color. +Each line will be set in a simple 8x8 font in the color it describes; thus, +any lines corresponding to the GIF's background color will be blank.<p> + +<H1>Usage:</H1> + +<pre> +gifcolor [-q] [-b Background] [-h] <ColorMapFile +</pre> + +As gifcolor can generate huge amounts of data, ^C will kill it, but 'q' will +stop only the printing (of one of -e, -z, -p), while file integrity will still +be checked.<P> + +<H1>Memory required:</H1> + +Line. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-b] +<DD> Set the image's backround color to a given numeric index.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifcomb.html b/giflib-4.1.6/doc/gifcomb.html new file mode 100644 index 0000000..2728835 --- /dev/null +++ b/giflib-4.1.6/doc/gifcomb.html @@ -0,0 +1,57 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifcomb</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifcomb</H1></CENTER> + +A program to combine 2 GIF images of exactly the same size into one. +The color maps are merged, but the result may not exceed 256 colors. +A boolean mask GIF file can be used to set which pixel from two images +to use at each location. Otherwise any background color from first +image is converted to second image color at that point. Only the +first image of each file is combined; again, all files' first images +must be of exactly the same size.<P> + +<H1>Usage:</H1> + +<pre> +gifcomb [-q] [-m MaskGIFFile] [-h] gif-file... +</pre> + +Two GIF files must be specified; a third mask GIF file is optional.<P> + +<H1>Memory required:</H1> + +Line. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Default off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-m MaskGIFFile] +<DD> the MaskGIFfile can be regular GIF file whose first + image has same dimensions as the combined images. Any non-background color + in it will select Image 1 Pixel to output, otherwise Image2 pixel will be + selected. Usually this image will be boolean (two colors only) but + it does not have to be.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifcompose.html b/giflib-4.1.6/doc/gifcompose.html new file mode 100644 index 0000000..7e56232 --- /dev/null +++ b/giflib-4.1.6/doc/gifcompose.html @@ -0,0 +1,124 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifcompose</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifcompose</H1></CENTER> + +The gifcompose program uses the GIFLIB utility tools to support a minilanguage +for describing GIF pasteup sequences.<P> + +<H1>Usage:</H1> + +<pre> +gifcompose [-v] <specfile +</pre> + +<H1>Specification Syntax</H1> + +The gifcompose tool takes a series of text lines and interprets them as +commands to do pasteup operations. The commands are:<P> + +<CENTER><H2>Generators</H2></CENTER> + +<DL> +<DT><CODE>gif <name></CODE><DD> + Paste in <name>.gif<P> + +<DT><CODE>raw <name> <width> <height></CODE><DD> + Paste in the given raw-format file (no suffix supplied). Raw format + is a stream of 8-bit indices into the EGA color map. Accordingly, the + width and height must be specified, and the source must be exactly + width times height bytes long.<P> + +<DT><CODE>rgb <name> <width> <height></CODE><DD> + Paste in the given RGB-format file (no suffix supplied). Raw format + is a stream of 24-bit color values. Accordingly, the width and height + must be specified, and the source must be exactly 3 times width times + height bytes long.<P> + +<DT><CODE>rle <name></CODE><DD> + Paste in the given RLE-format file (no suffix supplied). This converts + the Utah Raster Kit format to GIF.<P> + +<DT><CODE>text <text> [foreground <index>] [color <r> <g> <b>]</CODE><DD> + Copy 8x8 monospace font, with transparent background and index 1 as + foreground. If the text string contains whitespaces, they must be + escaped or the string must be quoted (shell conventions).<P> + + The optional suffix `foreground <n>' sets the foreground color index. + The optional suffix `color <r> <g> <b>' sets the RGB color to be used + for the foreground index.<P> +</DL> + +Each generator operation may be followed by any combination of the +following suffixes: + +<CENTER><H2>Modifiers</H2></CENTER> + +<DT><CODE>at <x> <y></CODE><DD> + Place the image at the given (upper-left-hand-corner) coordinates + in the pasted-up result.<P> + +<DT><CODE>clip <name> <top-x> <top-y> <bottom-x> <bottom-y></CODE><DD> + Clip image using the given rectange, paste it onto.<P> + +<DT><CODE>xflip</CODE><DD> + Flip the image around the X axis before placing it.<P> + +<DT><CODE>yflip</CODE><DD> + Flip the image around the Y axis before placing it.<P> + +<DT><CODE>left</CODE><DD> + Rotate the image 90 degrees counterclockwise before placing it.<P> + +<DT><CODE>right</CODE><DD> + Rotate the image 90 degrees clockwise before placing it.<P> + +<CENTER><H2>Target Operations</H2></CENTER> + +<DT><CODE>screen size <x-size> <y-size></CODE><DD> + Set the global screen size of the final image.<P> + +<DT><CODE>screen position <x> <y></CODE><DD> + Set the global screen position of the final image.<P> + +<CENTER><H2>Comments</H2></CENTER> + +Comments or comment lines may be preceded with `#' and will be ignored.<P> + +<H1>Memory required:</H1> + +Proportional to the size of the largest pasted image.<P> + +<H1>Options:</H1> + +<DL> +<DT> [-v] +<DD> Emit a report on each composition action to stderr as it happens. +</DL> + +<H1>Bugs:</H1> + +The suffix sequence `left left' sometimes mysteriously fails to work, +probably due to some restriction in <a href="gifflip.html">gifflip</a>.<P> + +No support for resizing or odd-angle rotations yet.<P> + +The `color' suffix of text is a no-op, because the present version of +<a href="gifovly.html">gifovly</a> throws away color tables.<P> + +Error checking is rudimentary.<P> + +<H1>Author:</H1> + +Eric S. Raymond <esr@snark.thyrsus.com> + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/giffiltr.html b/giflib-4.1.6/doc/giffiltr.html new file mode 100644 index 0000000..13a590e --- /dev/null +++ b/giflib-4.1.6/doc/giffiltr.html @@ -0,0 +1,40 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>giffiltr</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>giffiltr</H1></CENTER> + +This is an expensive way to copy a GIF. The source is included as a skeleton +for more sophisticated filters. See the source in the util directory for +details.<P> + +I suppose this does have some utility as a test of the sequential GIF record +I/O routines. The output should be bytewise identical to the input.<P> + +<H1>Usage:</H1> + +<pre> +giffiltr <GifFile >GifCopy +</pre> + +<H1>Memory required:</H1> + +Line. + +<H1>Options:</H1> + +None. + +<H1>Author</H1> + +Eric S. Raymond <esr@snark.thyrsus.com><P> + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/giffix.html b/giflib-4.1.6/doc/giffix.html new file mode 100644 index 0000000..c65ca32 --- /dev/null +++ b/giflib-4.1.6/doc/giffix.html @@ -0,0 +1,47 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>giffix</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>giffix</H1></CENTER> + +A program that attempts to fix broken GIF images. Currently will "fix" +images terminated prematurely by filling the rest of the image with +the darkest color found in image.<P> + +<H1>Usage:</H1> + +<pre> +giffix [-q] [-h] gif-file +</pre> + +If no gif-file is given, GifFix will try to read a GIF file from +stdin. The fixed file is dumped to stdout.<P> + +<H1>Memory required:</H1> + +Line. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above..<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifflip.html b/giflib-4.1.6/doc/gifflip.html new file mode 100644 index 0000000..a0c1106 --- /dev/null +++ b/giflib-4.1.6/doc/gifflip.html @@ -0,0 +1,60 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifflip</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifflip</H1></CENTER> + +A program to flip (mirror) GIF file along X or Y axes, or rotate the GIF +file 90 degrees to the left or to the right.<P> + +<H1>Usage:</H1> + +<pre> +gifflip [-q] [-r] [-l] [-x] [-y] [-h] gif-file +</pre> + +If no gif-file is given, GifFlip will try to read a GIF file from stdin.<P> + +<H1>Memory required:</H1> + +Image. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Default off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-r] +<DD> Rotate the GIF file to the right.<P> + +<DT> [-l] +<DD> Rotate the GIF file to the left.<P> + +<DT> [-x] +<DD> Mirror the GIF file along the X axis. Very useful if GIF file was + created from another format in with the first line in at image bottom. + Effectively exchanges first row with last.<P> + +<DT> [-y] +<DD> Mirror the GIF file along Y axis. + Effectively exchanges first column with last.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifhisto.html b/giflib-4.1.6/doc/gifhisto.html new file mode 100644 index 0000000..9992a9c --- /dev/null +++ b/giflib-4.1.6/doc/gifhisto.html @@ -0,0 +1,72 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifhisto</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifhisto</H1></CENTER> + +A program to create histogram of number of pixels using each color. The output +can be formatted into a GIF histogram file, or as text file - both go to +stdout.<P> + +<H1>Usage:</H1> + +<pre> +gifhisto [-q] [-t] [-s Width Height] [-n ImageNumber] [-b] [-h] gif-file +</pre> + +If no gif-file is given, GifHisto will try to read a GIF file from stdin.<P> + +<H1>Memory required:</H1> + +Line. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Default off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-t] +<DD> Force output to be text file of the following form: (colormap size) + lines each containing two integers: number of times color appeared, and + color index. Lines are in increasing color index order. This output can be + fed directly to a sort program if ordering by color frequency + is desired.<P> + + The colrmap picked is the one to be used for the image to generate + histogram for, as defined in GIF format.<P> + +<DT> [-s Width Height] +<DD> Size of GIF histogram file. The Height of the + histogram should be power of 2 dividable by number of colors in colormap.<P> + + Width sets the resolution (accuracy if you like) of the histogram as + the maximum histogram bar is scaled to fit it.<P> + +<DT> [-n ImageNumber] +<DD> Image number to test. Default is one.<P> + +<DT> [-b] +<DD> Zeros the background color count. As only linear scale bars are + supported and usually the background appears much more often then other + colors, deleting the background count will improve the scaling of other + colors. + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifinter.html b/giflib-4.1.6/doc/gifinter.html new file mode 100644 index 0000000..007186e --- /dev/null +++ b/giflib-4.1.6/doc/gifinter.html @@ -0,0 +1,51 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifinter</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifinter</H1></CENTER> + +A program to convert between interlaced and non-interlaced GIF images.<P> + +<H1>Usage:</H1> + +<pre> +gifinter [-q] [-i] [-s] [-h] gif-file +</pre> + +If no gif-file is given, GifInter will try to read a GIF file from stdin.<P> + + +<H1>Memory required:</H1> + +Image. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-i] +<DD> Force all images in GIF file be interlaced.<P> + +<DT> [-s] +<DD> Force all images in GIF file be sequential (default).<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifinto.html b/giflib-4.1.6/doc/gifinto.html new file mode 100644 index 0000000..635286c --- /dev/null +++ b/giflib-4.1.6/doc/gifinto.html @@ -0,0 +1,56 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifinto</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifinto</H1></CENTER> + +A program to save stdin into a file with given name, iff the result file has +size bigger than specified (see below). This can be used to save result in +same files name we started a chain of pipes.<P> + +<H1>Usage:</H1> + +<pre> +gifinto [-q] [-s MinFileSize] [-h] gif-file +</pre> + +Gifinto always reads a GIF file from stdin.<P> + +<H1>Memory required:</H1> + +Line. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Default off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-s MinFileSize] +<DD> If file is less than MinFileSize, it is deleted and + not renamed to given name. This will prevent killing the file we + started with if the result is an empty file, or the pipeline did not + complete.<P> + + The default file threshold size is 14 bytes which is 1 bigger than GIF file + stamp (6 bytes) and GIF file screen descriptor (7 bytes), so a GIF file with + only GIF stamp and screen descriptor will not be renamed.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifovly.html b/giflib-4.1.6/doc/gifovly.html new file mode 100644 index 0000000..d287baa --- /dev/null +++ b/giflib-4.1.6/doc/gifovly.html @@ -0,0 +1,49 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifovly</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifovly</H1></CENTER> + +This program takes a multi-image GIF file and generates a single GIF +consisting of all the images overlayed. Each image's screen position +is used. Thus, you can use this together with <a +href="gifpos.html">gifpos</a> and <a href="gifasm.html">gifasm</a> to +paste together images.<P> + +<H1>Usage:</H1> + +<pre> +gifovly [-s TransparentColor] [-h] +</pre> + +The GIF to be operated is read in from stdin. The result GIF is written to +stdout.<P> + +<H1>Memory required:</H1> + +Proportional to the size of the input file.<P> + +<H1>Options:</H1> + +<DL> +<DT> [-t num] +<DD> If this index is given, any pixel in images after the first that + has this value is not copied.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above..<P> +</DL> + +<H1>Author:</H1> + +Eric S. Raymond <esr@snark.thyrsus.com><P> + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifpos.html b/giflib-4.1.6/doc/gifpos.html new file mode 100644 index 0000000..b5999ab --- /dev/null +++ b/giflib-4.1.6/doc/gifpos.html @@ -0,0 +1,59 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifpos</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifpos</H1></CENTER> + +A program to change GIF screen size and/or reposition images. No test is made +to make sure changes will generate valid GIF files (i.e. images are still +confined to screen etc.)<P> + +<H1>Usage:</H1> + +<pre> +gifpos [-q] [-s Width Height] [-i Left Top] [-n n Left Top] [-h] gif-file +</pre> + +If no gif-file is given, GifPos will try to read a GIF file from stdin.<P> + +<H1>Memory required:</H1> + +Line. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Default off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-s Width Height] +<DD> Set the new screen dimensions, so for example + `-s 1000 800' will set screen to width of 1000 and height of 800.<P> + +<DT> [-i Left Top] +<DD> set image relative to screen position, so for example + `-i 100 80' will set image left position to 100 and top position to 80. + This sets the position of the first image only.<P> + +<DT> [-n n Left Top] +<DD> set image n relative to screen position, so for + example '-n 3 100 80' will set the third image position as in 2.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifrotat.html b/giflib-4.1.6/doc/gifrotat.html new file mode 100644 index 0000000..77bea98 --- /dev/null +++ b/giflib-4.1.6/doc/gifrotat.html @@ -0,0 +1,62 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifrotat</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifrotat</H1></CENTER> + +A program to rotate a GIF image by a specified angle.<P> + +<H1>Usage:</H1> + +<pre> +gifrotat -a Angle [-q] [-s Width Height] [-h] gif-file +</pre> + +If no gif-file is given, GifRotat will try to read a GIF file from stdin.<P> + + +<H1>Memory required:</H1> + +Screen (of source image).<P> + +<H1>Options:</H1> + +<DL> +<DT> -a Angle +<DD> Specifies the angle to rotate in degrees with respect to + the X (horizontal) axis.<P> + +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-s Width Height] +<DD> Since the rotated image will have the same image size as + the original, some parts of the image will by clipped out and lost. By + specifing a (bigger) size explicitly using the `-s' option, these parts + may be saved.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Notes:</H1> + +The image is rotated around its center. No filtering is performed on the +output, which have the same color map as the input. This is mainly since +filtering would require color quantization which is very memory/time intensive +and out of MSDOS memory limits even for small images.<P> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifrsize.html b/giflib-4.1.6/doc/gifrsize.html new file mode 100644 index 0000000..1797a20 --- /dev/null +++ b/giflib-4.1.6/doc/gifrsize.html @@ -0,0 +1,60 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifrsize</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifrsize</H1></CENTER> + +A program to resize image size by an integer factor, deleting bits when scaling +down and duplicating bits when scaling up.<P> + +<H1>Usage:</H1> + +<pre> +gifrsize [-q] [-S X Y] [-s Scale] [-x XScale] [-y YScale] [-h] gif-file +</pre> + +If no gif-file is given, GifRSize will try to read a GIF file from stdin.<P> + +<H1>Memory required:</H1> + +Line. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-S X Y] +<DD> specifies the exact screen dimension of the output GIF.<P> + +<DT> [-s Scale] +<DD> Set scaling factor for both x & y direction to Scale. + Default is 0.5. Note this is a floating point number.<P> + +<DT> [-x XScale] +<DD> Set scaling factor for x direction to Scale. Default is 0.5. + Note: this is a floating point number.<P> + +<DT> [-y YScale] +<DD> Set scaling factor for y direction to Scale. Default is 0.5. + Note: this is a floating point number.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifspnge.html b/giflib-4.1.6/doc/gifspnge.html new file mode 100644 index 0000000..412ca00 --- /dev/null +++ b/giflib-4.1.6/doc/gifspnge.html @@ -0,0 +1,40 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifspnge</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifspnge</H1></CENTER> + +This is an expensive way to copy a GIF. The source is included as a skeleton +for more sophisticated filters using DGifSlurp() and EGifSpew(). See the +source in the util directory for details.<P> + +I suppose this does have some utility as a test of DGifSlurp() and EGifSpew(). +The output should be bytewise identical to the input.<P> + +<H1>Usage:</H1> + +<pre> +gifspnge <GifFile >GifCopy +</pre> + +<H1>Memory required:</H1> + +The size of the input GIF, plus malloc overhead. + +<H1>Options:</H1> + +None. + +<H1>Author:</H1> + +Eric S. Raymond <esr@snark.thyrsus.com><P> + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/giftext.html b/giflib-4.1.6/doc/giftext.html new file mode 100644 index 0000000..5707795 --- /dev/null +++ b/giflib-4.1.6/doc/giftext.html @@ -0,0 +1,71 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>giftext</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>giftext</H1></CENTER> + +A program to dump (text only) general information about GIF file.<P> + +<H1>Usage:</H1> + +<pre> +giftext [-q] [-c] [-e] [-z] [-p] [-r] [-h] gif-file +</pre> + +If no gif-file is given, GifText will try to read a GIF file from stdin.<P> + +As giftext can generate huge amounts of data, ^C will kill it, but 'q' will +stop only the printing (of one of -e, -z, -p), while file integrity will still +be checked.<P> + +<H1>Memory required:</H1> + +Line. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-c] +<DD> Dumps the color maps.<P> + +<DT> [-e] +<DD> Dumps encoded bytes - the pixels after compressed using LZ + algorithm and chained to form bytes. This is the form the data is saved + in the GIF file. Dumps in hex - 2 digit per byte.<P> + +<DT> [-z] +<DD> Dumps the LZ codes of the image. Dumps in hex - 3 digits per + code (as we are limited to 12 bits).<P> + +<DT> [-p] +<DD> Dumps the pixels of the image. Dumps in hex - 2 digit per + pixel (<=byte).<P> + +<DT> [-r] +<DD> Dumps raw pixels as one byte per pixel. This option inhibits all + other options and only the pixels are dumped. This option may be used to + convert GIF files into raw data. Note: the color map can be extracted by + gifclrmp utility. If more than one image is included in the file, all + images will be dumped in order.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/gifwedge.html b/giflib-4.1.6/doc/gifwedge.html new file mode 100644 index 0000000..35ce5a5 --- /dev/null +++ b/giflib-4.1.6/doc/gifwedge.html @@ -0,0 +1,53 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>gifwedge</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>gifwedge</H1></CENTER> + +A program to create a test GIF image with intensity levels of the RGB colors +YCM colors and white.<P> + +<H1>Usage:</H1> + +<pre> +gifwedge [-q] [-l #Lvls] [-s SizeX SizeY] [-h] +</pre> + +<H1>Memory required:</H1> + +Line. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-l #Lvls] +<DD> Set number of intensity levels per color. This number must be + power of two up to 32, as Gif format can only have 256 color simultanuously + and 7 basic colors are to be displayed.<P> + +<DT> [-s SizeX SizeY] +<DD> Force image size to be SizeX by SizeY pixels. + Image size will be rounded down to be a multiple of number of intensities + horizontally, and 7 (colors) vertically.<P> + +<DT> [-h] +<DD> Print one line command line help, similar to Usage above.<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/icon2gif.html b/giflib-4.1.6/doc/icon2gif.html new file mode 100644 index 0000000..a68127e --- /dev/null +++ b/giflib-4.1.6/doc/icon2gif.html @@ -0,0 +1,142 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>icon2gif</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>icon2gif</H1></CENTER> + +A program to convert a series of editable text GIF icon specifications and +named GIF files into a multi-image GIF, usable as a graphic resource file. +It can also dump existing GIFs in this format.<P> + +<H1>Usage:</H1> + +<pre> +icon2gif [-q] [-a] [-d] [t TranslationTable] [-h] gif-file... +</pre> + +If no gif-file is given, icon2gif will try to read a text input from stdin.<P> + +<H1>Specification Syntax</H1> + +Here is a syntax summary in informal BNF. The token `NL' represents a +required newline.<P> + +<pre> +<gif-spec> ::= <header-block> <image-block>... + +<header-block> ::= <header-declaration>... + +<header-declaration ::= + | screen width <digits> NL + | screen height <digits> NL + | screen colors <digits> NL + | screen background <digits> NL + | screen map <color-table> NL + +<color-table> ::= <color-declaration>... end NL + +<color-declaration> ::= rgb <digits> <digits> <digits> is <key> NL + +<image-block> ::= include <file-name> NL + | image NL + <image-declaration>... + <raster-picture> + [ <extension> ] + +<image-declarations> ::= image top <digits> NL + | image left <digits> NL + | image interlaced NL + | image map <color-table> NL + | image bits <digits> by <digits> NL <raster-block> + +<extension> := <comment> NL <extension-block> NL end NL + | <plaintext> NL <extension-block> NL end NL + | extension <hex-digits> NL <extension-block> NL end NL +</pre> + +If the semantics of the `screen height', `screen width', `screen background', +`image top', `image left' declarations aren't obvious to you, what are you +doing with this software?<P> + +A color table declares color indices (in ascending order from 0) and +assiciates them with key characters. These characters can later be used in +raster blocks. As these must be printable and non-whitespace, you can only +specify 94 colors per icon. Life is like that sometimes.<P> + +A raster block is just a block of key characters. It should be sized correctly +for the `image bits' declaration that leads it.<P> + +The `comment' or `plaintext' keywords lead defined GIF89 extension +record data (the other two GIF89 types, graphics control and application +block, are not yet supported). You can also say `extension' followed +by a hexadecimal record type. All of these extension declarations +must be followed by an extension block, which is terminated by the +keyword `end' on its own line.<P> + +An extension block is a series of text lines, each interpreted as a string of +bytes to fill an argument block (the terminating newline is stripped). Text +may include standard C-style octal and hex escapes preceded by a backslash.<P> + +All <digits> tokens are interpreted as decimal numerals; <hex-digits> +tokens are interpreted as two hex digits (a byte). All coordinates are +zero-origin with the top left corner (0,0). Range checking is weak and +signedness checking nonexistent; caveat hacker!<P> + +In general, the amount of whitespace and order of declarations within a +header or image block is not significant, except that a raster picture +must immediately follow its `image bits' bits declaration.<P> + +The `include' declaration includes a named GIF as the next image. The global +color maps of included GIFs are merged with the base table defined by any +`screen color' declaration. All images of an included multi-image GIF will +be included in order.<P> + +Comments may be preceded with `#' and will be ignored.<P> + +<H1>Memory required:</H1> + +For the compilation mode, proportional to the size of the input file. For +dumping, proportional to the line size of the widest GIF.<P> + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-d] +<DD> Dump the input GIF file(s) into the text form described above.<P> + +<DT> [-t] +<DD> Specify name characters to use when dumping raster blocks. Only + valid with -d option.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Bugs:</H1> + +Because there are only 94 characters unambiguously usable for raster blocks, +an attempt to dump a GIF with a larger color map will fail.<P> + +Error checking is rudimentary.<P> + +<H1>Example:</H1> + +A sample icon file called `sample.ico' is included in the pic directory.<P> + +<H1>Author:</H1> + +Eric S. Raymond <esr@snark.thyrsus.com> + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/index.html b/giflib-4.1.6/doc/index.html new file mode 100644 index 0000000..0b62c0c --- /dev/null +++ b/giflib-4.1.6/doc/index.html @@ -0,0 +1,215 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>Introduction to GIFLIB</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +<CENTER><H1>Introduction to GIFLIB</H1></CENTER> + +GIFLIB is a package of portable tools and library routines for working +with GIF images. You can find the latest version at the GIFLIB home +page <a +href="http://www.ccil.org/~esr/giflib">http://www.ccil.org/~esr/giflib</a>.<P> + +The Graphics Interchange Format(c) specification is the copyrighted +property of CompuServe Incorporated. GIF(sm) is a service mark +property of CompuServe Incorporated. As this package existed before +UniSys's lawyeritis attack of New Years' Day 1995, it is grandfathered +in under their license terms and you do <em>not</em> have to pay fees +for using it.<P> + +This package has been released under an X Consortium-life freeware +license. Use and copy as you see fit. If you make useful changes, +add new tools, or find and fix bugs, please send your mods to the +maintainers for general distribution.</P> + +The util directory includes programs to clip, rotate, scale, and +position GIF images. It includes an X11 viewer, code to dump GIFs to +an Epson-compatible printer in graphics mode, and many conversion +utilities. These are no replacement for an interactive graphics +editor, but they can be very useful for scripted image generation or +transformation.<P> + +The library includes program-callable entry points for reading and writing +GIF files, an 8x8 utility font for embedding text in GIFs, and an error +handler. GIF manipulation can be done at a relatively low level by +sequential I/O (which automatically does/undoes image compression) or at +a higher level by slurping an entire GIF into allocated core.<P> + +This library speaks both GIF87a and GIF89. The differences between +GIF87 and GIF89 are minor: in the latter, the interpretation of some +extension block types is defined. The library never needs to actually +interpret these, but <a href="giftext.html">giftext</a> notices them.<P> + +<H1>Utilities</H1> + +Here is a summary of the utilities in this package. If you're looking +at this page through a web browser, each utility name should be a +hotlink to HTML documentation.<P> + +<H2>Conversion Utilities</H2> + +<DL> +<DT><a href="gif2bgi.html">gif2bgi</a> +<DD>display GIFs on IBM PC displays using the BGI (Borland) driver +<DT><a href="gif2epsn.html">gif2epsn</a> +<DD>dump images saved as GIF files on Epson type printers +<DT><a href="gif2herc.html">gif2herc</a> +<DD>display GIFs on IBM PC displays using the Hercules graphic card +<DT><a href="gif2iris.html">gif2iris</a> +<DD>display GIFs under SGI NeWs window system +<DT><a href="gif2ps.html">gif2ps</a> +<DD>print GIF file on laser printers supporting PostScript +<DT><a href="gif2rgb.html">gif2rgb</a> +<DD>convert images saved as GIF to 24-bit RGB image(s) +<DT><a href="gif2rle.html">gif2rle</a> +<DD>convert images saved as GIF to RLE (Utah raster toolkit) format +<DT><a href="gif2x11.html">gif2x11</a> +<DD>display images saved as GIF files under X window system +<DT><a href="raw2gif.html">raw2gif</a> +<DD>convert raw 8-bit image data into GIF files +<DT><a href="rgb2gif.html">rgb2gif</a> +<DD>convert 24 bit images to a GIF image using color quantization +<DT><a href="rle2gif.html">rle2gif</a> +<DD>convert images saved as RLE (Utah raster toolkit) to GIF format +</DL> + +<H2>Test Pattern Generators</H2> + +<DL> +<DT><a href="gifbg.html">gifbg</a> +<DD>generate a single-color test pattern GIF +<DT><a href="gifcolor.html">gifcolor</a> +<DD>generate color test patterns +<DT><a href="gifwedge.html">gifwedge</a> +<DD>create a test GIF image resembling a color monitor test pattern +</DL> + +<H2>Image Manipulation Components</H2> + +<DL> +<DT><a href="gifasm.html">gifasm</a> +<DD>assemble multiple GIFs into one, or burst a multiple-mage GIF +<DT><a href="gifclip.html">gifclip</a> +<DD>clip or crop a GIF image +<DT><a href="gifclrmp.html">gifclrmp</a> +<DD>modify GIF image colormaps +<DT><a href="gifcomb.html">gifcomb</a> +<DD>combine 2 GIF images of exactly the same size into one +<DT><a href="giffix.html">giffix</a> +<DD>clumsily attempts to fix truncated GIF images +<DT><a href="gifflip.html">gifflip</a> +<DD>flip GIF image along X or Y axis or rotate by 90 degrees +<DT><a href="gifinter.html">gifinter</a> +<DD>convert between interlaced and non interlaced images +<DT><a href="gifovly.html">gifovly</a> +<DD>generate one composite GIF from a multiple-image GIF +<DT><a href="gifpos.html">gifpos</a> +<DD>change a GIF's screen size or recondition it. +<DT><a href="gifrotat.html">gifrotat</a> +<DD>rotate a GIF through any desired angle +<DT><a href="gifrsize.html">gifrsize</a> +<DD>resize a GIF by deletion or duplication of bits +<DT><a href="gifburst.html">gifburst</a> +<DD>burst a GIF image into subrectangles. +</DL> + +<H2>Report Generators</H2> + +<DL> +<DT><a href="giftext.html">giftext</a> +<DD>print (text only) general information about a GIF +<DT><a href="gifhisto.html">gifhisto</a> +<DD>generate color-frequency histogram from a GIF +</DL> + +<H2>GIF Composition Tools</H2> + +<DL> +<DT><a href="icon2gif.html">icon2gif</a> +<DD>converter/deconverter to/from an editable text format +<DT><a href="text2gif.html">text2gif</a> +<DD>generate GIF images out of regular text in 8x8 font +<DT><a href="gifinto.html">gifinto</a> +<DD>end-of-pipe fitting for GIF-processing pipelines +<DT><a href="gifcompose.html">gifcompose</a> +<DD>use giflib tools to compose images +</DL> + +<H2>C Code Templates</H2> + +<DL> +<DT><a href="giffiltr.html">giffiltr</a> +<DD>template code for filtering a GIF sequentially +<DT><a href="gifspnge.html">gifspnge</a> +<DD>template code for filtering a GIF with in-core operations +</DL> + +Under MS-DOS, most filters will print the current input scan line number +(counting up) whenever they read image input, and will print output image line +number (counting down) when they dump output. Utilities that only read or +write always print in increasing order. Utilities (like GifPos that only +change positions) that copy the image as a block of compressed data will print +nothing --- they cannot identify a scan line number, and are enough faster that +the feedback to the user doesn't seem necessary.<P> + +Some of the utilities require memory on the order of the whole screen, while +others read one scan line at a time. Each utility HTML file has entry called +<em>Memory Usage</em> which will be one of:<P> + +<DL> +<DT> Line <DD> memory required is on the order of one scan line +<DT> Image <DD> proportional to the size of the biggest image in GIF file +<DT> Screen <DD> proportional to GIF screen size +</DL> + +In all cases a byte is allocated per pixel, so an image of 320 by 200 pixels +will requires approximately 64k bytes of main memory.<P> + +<H1>Library Functions</H1> + +The library contains two groups of C functions. One group does sequential +I/O on the stream-oriented GIF format. The other supports grabbing an +entire GIF into allocated core, operating on it in core, and then writing +the modified in-core GIF out to disk.<P> + +Unless you are on a 286 or some other very memory-limited machine +running under DOS, you probably want to use the second group.<P> + +Detailed documentation on the library entry points is in <a +href="gif_lib.html">gif_lib.html</a>. Library error codes are +described in <a href="liberror.html">liberror.html</a><P> + +<H1>The GIF Standard</H1> + +The doc subdurector includes flat-ASCII descriptions of <a +href="gif89.txt">GIF89 format</a> and <a href="lzgif.txt">Lempel-Ziv +Compression</a>.<P> + +<H1>History</H1> + +This package was originally written by Gershon Elber <gershon@cs.utah.edu> +in 1990 on an IBM PC under MS-DOS using Borland Turbo C. He made it portable +to several UNIX environments.<P> + +The 2.1 version featured substantial changes and additions by Eric +S. Raymond <esr@snark.thyrsus.com>. These included the +DGifSlurp/EGifSpew function pair for enabling non-sequential +operations on GIF images and the tools icon2gif, gifovly, gifburst, and +gifcompose.<P> + +The 2.4 version converted all the docs from an idiosyncratic +plain-text formal to to HTML.<P> + +<H1>Package Status</H1> + +GIFLIB's current maintainer is Eric S. Raymond. You can find his home +page at <a href="http://www.ccil.org/esr">http://www.ccil.org/esr</a>.<P> + +GIFLIB is not under active development, but bug fixes are being accepted.<P> + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/liberror.html b/giflib-4.1.6/doc/liberror.html new file mode 100644 index 0000000..35356b3 --- /dev/null +++ b/giflib-4.1.6/doc/liberror.html @@ -0,0 +1,140 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>GIFLIB error codes</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>GIFLIB error codes</H1></CENTER> + +Errors as reported from the GIF_LIB library are divided to two major +categoriess: the encoder (errors prefixed by E_GIF_ERR), and the +decoder (errors prefixed by D_GIF_ERR). This document explains them +briefly:<P> + +<H1>Encoding errors:</H1> + +<DL> +<DT><CODE>E_GIF_ERR_OpenFailed</CODE><DD> + Message printed using PrintGifError: "Failed to open given file" + IO error result when attempt to open the given GIF file.<P> + +<DT><CODE>E_GIF_ERR_WriteFailed</CODE><DD> + Message printed using PrintGifError: "Failed to Write to given file" + IO error result when attempt to write to the given GIF file.<P> + +<DT><CODE>E_GIF_ERR_HasScrnDscr</CODE><DD> + Message printed using PrintGifError: "Screen Descriptor already been set" + Attempt to write second screen descriptor to same GIF file. GIF file should + have exactly one screen descriptor which should be set directly after the + file is opened.<P> + +<DT><CODE>E_GIF_ERR_HasImagDscr</CODE><DD> + Message printed using PrintGifError: "Image Descriptor is still active" + Image descriptor should be sent before and image dump, and no second + image descriptor should be sent before current image dump ended. This error + occurred probably because current image was not complete.<P> + +<DT><CODE>E_GIF_ERR_NoColorMap</CODE><DD> + Message printed using PrintGifError: "Neither Global Nor Local color map" + An image must have either global (screen) or local (image) color map. + Neither were given in this case.<P> + +<DT><CODE>E_GIF_ERR_DataTooBig</CODE><DD> + Message printed using PrintGifError: "#Pixels bigger than Width * Height" + The number of pixels dumped for this image is bigger than specified by + image Height times image Width.<P> + +<DT><CODE>E_GIF_ERR_NotEnoughMem</CODE><DD> + Message printed using PrintGifError: "Fail to allocate required memory" + Once an attemp is made to open GIF file, special structures are allocated + to hold internal data for it. If allocation fails this error is returned.<P> + +<DT><CODE>E_GIF_ERR_DiskIsFull</CODE><DD> + Message printed using PrintGifError: "Write failed (disk full?)" + Writing encoded data failed.<P> + +<DT><CODE>E_GIF_ERR_CloseFailed</CODE><DD> + Message printed using PrintGifError: "Failed to close given file" + Closing file failed.<P> + +<DT><CODE> E_GIF_ERR_NotWriteable</CODE><DD> + Message printed using PrintGifError: "Given file was not opened for write" + GIF files can be opened both for read (DGIF part of library) and write + (EGIF part of library). This error occurs when a file is opened for read + (using DGIF) is given to one of the encoding (EGIF) routines.<P> +</DL> + +<H1>Encoding errors:</H1> + +<DL> +<DT><CODE>D_GIF_ERR_OpenFailed</CODE><DD> + Message printed using PrintGifError: "Failed to open given file" + IO error result when attempt to open the given GIF file.<P> + +<DT><CODE>D_GIF_ERR_ReadFailed</CODE><DD> + Message printed using PrintGifError: "Failed to Read from given file" + IO error result when attempt to write to the given GIF file.<P> + +<DT><CODE>D_GIF_ERR_Notgif-file$</CODE><DD> + Message printed using PrintGifError: "Given file is NOT GIF file" + GIF files should have special stamp identifies them as such, If that stamp + is not found, this error is issued.<P> + +<DT><CODE>D_GIF_ERR_NoScrnDscr</CODE><DD> + Message printed using PrintGifError: "No Screen Descriptor detected" + Each GIF file should have screen descriptor in its header. This error will + be generated if no such descriptor was found.<P> + +<DT><CODE>D_GIF_ERR_NoImagDscr</CODE><DD> + Message printed using PrintGifError: "No Image Descriptor detected" + Each image should have image descriptor in its header. This error will + be generated if no such descriptor was found.<P> + +<DT><CODE>D_GIF_ERR_NoColorMap</CODE><DD> + Message printed using PrintGifError: "Neither Global Nor Local color map" + An image must have either global (screen) or local (image) color map. + Neither were given in this case.<P> + +<DT><CODE>D_GIF_ERR_WrongRecord</CODE><DD> + Message printed using PrintGifError: "Wrong record type detected" + Each record in GIF file has special identifier, in its header. If the + record has wrong identifier, this error is generated.<P> + +<DT><CODE>D_GIF_ERR_DataTooBig</CODE><DD> + Message printed using PrintGifError: "#Pixels bigger than Width * Height" + The number of pixels dumped for this image is bigger than specified by + image Height times image Width.<P> + +<DT><CODE>D_GIF_ERR_NotEnoughMem</CODE><DD> + Message printed using PrintGifError: "Fail to allocate required memory" + Once an attemp is made to open GIF file, special structures are allocated + to hold internal data for it. If allocation fails this error is returned.<P> + +<DT><CODE>D_GIF_ERR_CloseFailed</CODE><DD> + Message printed using PrintGifError: "Failed to close given file" + Closing file failed.<P> + +<DT><CODE>D_GIF_ERR_NotReadable</CODE><DD> + Message printed using PrintGifError: "Given file was not opened for read" + GIF files can be opened both for read (DGIF part of library) and write + (EGIF part of library). This error occurs when a file is opened for write + (using EGIF) is given to one of the decoding (DGIF) routines.<P> + +<DT><CODE>D_GIF_ERR_ImageDefect</CODE><DD> + Message printed using PrintGifError: "Image is defective, decoding aborted" + This error is generated, once the decoding failed - probably image is + defect.<P> + +<DT><CODE>D_GIF_ERR_EOFTooSoon</CODE><DD> + Message printed using PrintGifError: "Image EOF detected, before image complete" + This error is generated once EOF code is detected in encoded image before + all the pixels (Width * Height) has be decoded.<P> +</DL> + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/lzgif.txt b/giflib-4.1.6/doc/lzgif.txt new file mode 100644 index 0000000..526b3ff --- /dev/null +++ b/giflib-4.1.6/doc/lzgif.txt @@ -0,0 +1,123 @@ +LZW compression used to encode/decode a GIF file by Bob Montgomery [73357,3140] + +ENCODER +Consider the following input data stream in a 4 color (A, B, C, D) system. +We will build a table of codes which represent strings of colors. Each time +we find a new string, we will give it the next code, and break it into a +prefix string and a suffix color. The symbols \ or --- represent the prefix +string, and / represents the suffix color. The first 4 entries in the table +are the 4 colors with codes 0 thru 3, each of which represents a single +color. The next 2 codes (4 and 5) are the clear code and the end of image +code. The first available code to represent a string of colors is 6. Each +time we find a new code, we will send the prefix for that code to the +output data stream. + +A B A B A B A B B B A B A B A A C D A C D A D C A B A A A B A B ..... +\/\/---/-----/\/---/-------/\/ \/ \ /\/---/---/\ /\/-----/---/---/ +6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Code + 6 8 10 8 14 16 8 13 7 Prefix + +The encoder table is built from input data stream. Always start with the +suffix of last code, and keep getting colors until you have a new +combination. + +Color Code Prefix Suffix String Output + A 0 - + B 1 - + C 2 - + D 3 - +Clear 4 - +End 5 - + A \ A A First color is a special case. + B / \ 6 A B AB A + A | / 7 B A BA B + B | + A / | 8 6 A ABA 6 + B | + A | + B \ / 9 8 B ABAB 8 + B / | 10 B B BB B + B | + A | / 11 10 A BBA 10 + B | + A | + B | + A / \ 12 9 A ABABA 9 + A \ / 13 A A AA A + C / \ 14 A C AC A + D \ / 15 C D CD C + A / | 16 D A DA D + C | + D | / 17 14 D ACD 14 + A | + D / \ 18 16 D DAD 16 + C \ / 19 D C DC D + A / | 20 C A CA C + B | + A | + A | / 21 8 A ABAA 8 + A | + B / | 22 13 B AAB 13 + A | + B / 23 7 B BAB 7 + +The resultant output stream is: A B 6 8 B 10 9 A A C D 14 16 D C 8 .... +The GIF encoder starts with a code length of 2+1=3 bits for 4 colors, so +when the code reaches 8 we will have to increase the code size to 4 bits. +Similarly, when the code gets to 16 we will have to increse the code size +to 5 bits, etc. If the code gets to 13 bits, we send a clear code and start +over. See GIFENCOD.GIF for a flow diagram of the encoding process. This +uses a tree method to search if a new string is already in the table, which +is much simpler, faster, and easier to understand than hashing. + +=========================================================================== + +DECODER + +We will now see if we can regenerate the original data stream and duplicate +the table looking only at the output data stream generated by the encoder +on the previous page. The output data stream is: + + A B 6 8 B 10 9 A A C D 14 16 D C 8 .... + +The docoding process is harder to see, but easier to implement, than the +encoding process. The data is taken in pairs, and a new code is assigned to +each pair. The prefix is the left side of the pair, and the suffix is the +color that the right side of the pair decomposes to from the table. The +decomposition is done by outputing the suffix of the code, and using the +prefix as the new code. The process repeats until the prefix is a single +color, and it is output too. The output of the decomposition is pushed onto +a stack, and then poped off the stack to the display, which restores the +original order that the colors were seen by the encoder. We will go thru +the first few entries in detail, which will hopefully make the process +clearer. + The first pair is (A B), so the prefix of code 6 is A and the suffix +is B, and 6 represents the string AB. The color A is sent to the display. + The 2nd pair is (B 6), so the prefix of code 7 is B and the suffix is +the the last color in the decomposition of code 6. Code 6 decomposes into +BA, so code 7 = BA, and has a suffix A. The color B is sent to the display. + The 3rd pair is (6 8) and the next code is 8. How can we decompose 8. +We know that the prefix of code 8 is 6, but we don't know the suffix. The +answer is that we use the suffix of the prefix code; A in this case since +the suffix of 6 is A. Thus, code 8 = ABA and has a suffix A. We decompose 6 +to get BA, which becomes AB when we pop it off the stack to the display. + The 4th pair is (8 B), so code 9 has a prefix of 8 and a suffix of B, +and code 9 = ABAB. We output ABA to the stack, and pop it off to the +display as ABA. + The 5th pair is (B 10) and the next code is 10. The prefix of code 10 +is B and the suffix is B (since the prefix is B). Code 10 = BB, and we +output the prefix B to the display. + The 6th pair is (10 9) and the next code is 11. Thus the prefix of +code 11 is 10 and the suffix is the last color in the decomposition of 9, +which is A. Thus code 11 = BBA, And we output BB to the display. + So far, we have output the correct colors stream A B AB ABA B BB to +the display, and have duplicated the codes 6 thru 11 in the encoder table. +This process is repeated for the whole data stream to reconstruct the +original color stream and build a table identical to the one built by the +encoder. We start the table with codes 0-5 representing the 4 colors, the +clear code, and the end code. When we get to code 8, we must increse the +code size to 5 bits, etc. See GIFDECOD.GIF for a flow diagram of the +decoding process. + +I Hope this helps take some of the mystery out of LZW compression, which is +really quite easy once you 'see' it. Bob Montgomery diff --git a/giflib-4.1.6/doc/raw2gif.html b/giflib-4.1.6/doc/raw2gif.html new file mode 100644 index 0000000..5870ba5 --- /dev/null +++ b/giflib-4.1.6/doc/raw2gif.html @@ -0,0 +1,60 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>raw2gif</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>raw2gif</H1></CENTER> + +A program to convert RAW image data into GIF files. Only one image can be +handled. The RAW image file is assumed to hold one pixel color in one byte, +and therefore the file size must be Width times Height as specified by the +-s option below.<P> + +<H1>Usage:</H1> + +<pre> +raw2gif [-q] -s Width Height [-p ColorMapFile] [-h] RawFile +</pre> + +If no RawFile is given, Raw2Gif will try to read RAW data from stdin. +The generated GIF File is dumped to stdout.<P> + +<H1>Memory required:</H1> + +Line. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> -s Width Height +<DD> the dimensions of the image MUST be specified in the + command line. The RAW image file size must be exactly Width times Height + bytes (each byte is one pixel color).<P> + +<DT> [-p ColorMapFile] +<DD> Color map to load for given RAW image. This file has + 4 integers in line (ColorIndex Red Green Blue), and the ColorIndex is + in order starting from 1. See GifClrMp, which can also use/create these + bitmap files. If no color map is specified, uses the EGA 16 color pallete + as default color map.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/rgb2gif.html b/giflib-4.1.6/doc/rgb2gif.html new file mode 100644 index 0000000..e21b3dc --- /dev/null +++ b/giflib-4.1.6/doc/rgb2gif.html @@ -0,0 +1,59 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>rgb2gif</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>rgb2gif</H1></CENTER> + +A program to convert 24 bit images to a GIF image using color quantization.<P> + + +<H1>Usage:</H1> + +<pre> +rgb2gif [-q] [-c #Colors] [-1] -s Width Height [-h] RGBFile +</pre> + +If no RGBFile is given, RGB2Gif will try to read a GIF file from stdin.<P> + +<H1>Memory required:</H1> + +Screen. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Defaulte off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-c #Colors] +<DD> Specifies number of colors to use, in bits per pixels, so + '-c 8' specifies actually 256 colors (maximum and default).<P> + +<DT> [-1] +<DD> Only one file in the format of RGBRGB... triplets (Each of R, G, B + is a byte) is read from input. This file size is 3 * Width * Height (see + '-s' below. If stdin is used for input, this option is implicitly applied. + The default (if not '-1') is 3 files with the names RGBFile.R, RGBFile.G, + RGBFile.B, each of which is Width * Height bytes.<P> + +<DT> [-s Width Height] +<DD> Specifies the size of the image to read.<P> + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above.<P> +</DL> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/rle2gif.html b/giflib-4.1.6/doc/rle2gif.html new file mode 100644 index 0000000..8d56206 --- /dev/null +++ b/giflib-4.1.6/doc/rle2gif.html @@ -0,0 +1,58 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>rle2gif</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>rle2gif</H1></CENTER> + +A program to convert images saved as RLE (Utah raster toolkit) to GIF +format.<P> + +<H1>Usage:</H1> + +<pre> +rle2Gif [-q] [-c #Colors] [-h] RleFile +</pre> + +If no RleFile is given, Rle2Gif will try to read an Rle file from stdin.<P> + +<H1>Memory required:</H1> + +Screen. + +<H1>Options:</H1> + +<DL> +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT> [-c #Colors] +<DD> Select size of color map in the output Gif file. #Colors + should be given as the based 2 log of number of colors. Default is 8 + which is 256 colors, and which is also the maximum. + +<DT> [-h] +<DD> Print one line of command line help, similar to Usage above..<P> +</DL> + +<H1>Notes:</H1> + +As the RLE format allows full 24 bits per pixel (8 per primary color) +Colors must be quantized to the number of colors as set by the [-c] +option, above. This process is quite slow. See the quantize.c file +in the lib directory for the code for this quantization algorithm +(median cut).<P> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> diff --git a/giflib-4.1.6/doc/text2gif.html b/giflib-4.1.6/doc/text2gif.html new file mode 100644 index 0000000..f44d4fc --- /dev/null +++ b/giflib-4.1.6/doc/text2gif.html @@ -0,0 +1,73 @@ +<!doctype HTML public "-//W3O//DTD W3 HTML 2.0//EN"> +<HTML> +<HEAD> +<TITLE>text2gif</TITLE> +<link rev=made href=mailto:esr@snark.thyrsus.com> +</HEAD> +<BODY> +Go to <a href="index.html">index page</a>. + +<CENTER><H1>text2gif</H1></CENTER> + +A program to generate GIF images out of regular text. Text can be one line +or multi-line, and is converted using 8 by 8 fixed font.<P> + +<H1>Usage:</H1> + +<pre> +text2gif [-q] [-s ClrMapSize] [-f FGClr] [-c R G B] [-t "Text"] [-h] +</pre> + +This program reads stdin if no text is provided on the command line (-t), +and will dump the created GIF file to stdout.<P> + +<H1>Memory required:</H1> + +Line. + +<H1>Options:</H1> + +<DT> [-q] +<DD> Quiet mode. Defaults off on MSDOS, on under UNIX. Controls printout + of running scan lines. Use -q- to invert.<P> + +<DT>[-s ClrMapSize] +<DD>Explicitly defines the size of the color map of the + resulting gif image. Usually the image will be bicolor with fg as color + 1, unless [-f] is explicitly given in case the color map size will be + big enough to hold it. However it is sometimes convenient to set the + color map size to certain size while the fg color is small mainly so + this image may be merged with another (images must match color map size).<P> + +<DT>[-f FG] +<DD> Select foreground index (background is always 0). By default + it is one and therefore the image result is bicolored. + if FG is set to n then color map will be created with 2^k entries where + 2^k > n for minimum k, assuming k <= 8. This color map will be all zeros + except this forground index. This option is useful if this text image + should be integrated into other image colormap using their colors.<P> + +<DT> [-c R G B] +<DD> The color to use as the foreground color. White by default.<P> + +<DT> [-t "Text"] +<DD> One line of text can be provided on the command + line. Note you must encapsulate the Text within quotes if it has spaces + (The quotes themselves are not treated as part of the text). If no -t + option is provided, stdin is read until end of file.<P> + +<DT> [-h] +<DD> Print one line command line help, similar to Usage above.<P> + +<H1>Notes:</H1> + +There is a hardcoded limit of 100 the number of lines.<P> + +<H1>Author:</H1> + +Gershon Elber + +<HR> +<ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS> +</BODY> +</HTML> |
