Implement sharpen

bug:7279964
bug:7247494
bug:7234321

- add a sharpen filter
- add infrastructure to use RenderScript
- some refactoring (add an ImageSlave class)
- add new zoom UI

Change-Id: Id94dc94d32866c7107b6818adf4db35d0c6c0b01

17 files changed, 576 insertions, 100 deletions

diff --git a/Android.mk b/Android.mk
index 1e4430bee..e2914bb3a 100644
--- a/Android.mk
+++ b/Android.mk
@@ -8,7 +8,7 @@ LOCAL_STATIC_JAVA_LIBRARIES := android-support-v13
 LOCAL_STATIC_JAVA_LIBRARIES += com.android.gallery3d.common2
 LOCAL_STATIC_JAVA_LIBRARIES += mp4parser
 
-LOCAL_SRC_FILES := $(call all-java-files-under, src)
+LOCAL_SRC_FILES := $(call all-java-files-under, src) $(call all-renderscript-files-under, src)
 LOCAL_SRC_FILES += $(call all-java-files-under, src_pd)
 LOCAL_SRC_FILES += $(call all-java-files-under, ../Camera/src)
 
diff --git a/res/layout/filtershow_activity.xml b/res/layout/filtershow_activity.xml
index 0dead607f..1449f16e9 100644
--- a/res/layout/filtershow_activity.xml
+++ b/res/layout/filtershow_activity.xml
@@ -125,6 +125,12 @@
                 android:layout_height="wrap_content"
                 android:visibility="gone" />
 
+            <com.android.gallery3d.filtershow.imageshow.ImageZoom
+                android:id="@+id/imageZoom"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:visibility="gone" />
+
             <ImageButton
                 android:id="@+id/showOriginalButton"
                 android:layout_width="64dip"
diff --git a/src/com/android/gallery3d/filtershow/FilterShowActivity.java b/src/com/android/gallery3d/filtershow/FilterShowActivity.java
index 694f51290..389973e50 100644
--- a/src/com/android/gallery3d/filtershow/FilterShowActivity.java
+++ b/src/com/android/gallery3d/filtershow/FilterShowActivity.java
@@ -11,6 +11,7 @@ import com.android.gallery3d.filtershow.imageshow.ImageBorder;
 import com.android.gallery3d.filtershow.imageshow.ImageShow;
 import com.android.gallery3d.filtershow.imageshow.ImageSmallFilter;
 import com.android.gallery3d.filtershow.imageshow.ImageStraighten;
+import com.android.gallery3d.filtershow.imageshow.ImageZoom;
 import com.android.gallery3d.filtershow.presets.*;
 import com.android.gallery3d.filtershow.provider.SharedImageProvider;
 import com.android.gallery3d.filtershow.tools.SaveCopyTask;
@@ -19,6 +20,7 @@ import com.android.gallery3d.R;
 
 import android.net.Uri;
 import android.os.Bundle;
+import android.renderscript.RenderScript;
 import android.annotation.TargetApi;
 import android.app.ActionBar;
 import android.app.Activity;
@@ -57,6 +59,7 @@ public class FilterShowActivity extends Activity implements OnItemClickListener,
     private ImageCurves mImageCurves = null;
     private ImageBorder mImageBorders = null;
     private ImageStraighten mImageStraighten = null;
+    private ImageZoom mImageZoom = null;
 
     private View mListFx = null;
     private View mListBorders = null;
@@ -100,6 +103,8 @@ public class FilterShowActivity extends Activity implements OnItemClickListener,
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
+        ImageFilterRS.setRenderScriptContext(this);
+
         setContentView(R.layout.filtershow_activity);
         ActionBar actionBar = getActionBar();
         actionBar.setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM);
@@ -121,11 +126,13 @@ public class FilterShowActivity extends Activity implements OnItemClickListener,
         mImageCurves = (ImageCurves) findViewById(R.id.imageCurves);
         mImageBorders = (ImageBorder) findViewById(R.id.imageBorder);
         mImageStraighten = (ImageStraighten) findViewById(R.id.imageStraighten);
+        mImageZoom = (ImageZoom) findViewById(R.id.imageZoom);
 
         mImageViews.add(mImageShow);
         mImageViews.add(mImageCurves);
         mImageViews.add(mImageBorders);
         mImageViews.add(mImageStraighten);
+        mImageViews.add(mImageZoom);
 
         mListFx = findViewById(R.id.fxList);
         mListBorders = findViewById(R.id.bordersList);
@@ -211,6 +218,8 @@ public class FilterShowActivity extends Activity implements OnItemClickListener,
         mImageBorders.setMaster(mImageShow);
         mImageStraighten.setImageLoader(mImageLoader);
         mImageStraighten.setMaster(mImageShow);
+        mImageZoom.setImageLoader(mImageLoader);
+        mImageZoom.setMaster(mImageShow);
 
         Intent intent = getIntent();
         String data = intent.getDataString();
@@ -688,11 +697,23 @@ public class FilterShowActivity extends Activity implements OnItemClickListener,
             @Override
             public void onClick(View v) {
                 hideImageViews();
-                mImageShow.setVisibility(View.VISIBLE);
+                mImageZoom.setVisibility(View.VISIBLE);
+                mImageZoom.setShowControls(true);
+                ImagePreset preset = mImageZoom.getImagePreset();
+                ImageFilter filter = preset.getFilter("Sharpen");
+                if (filter == null) {
+                    ImageFilterSharpen sharpen = new ImageFilterSharpen();
+                    ImagePreset copy = new ImagePreset(preset);
+                    copy.add(sharpen);
+                    copy.setHistoryName(sharpen.getName());
+                    copy.setIsFx(false);
+                    filter = copy.getFilter("Sharpen");
+                    mImageZoom.setImagePreset(copy);
+                }
+                mImageZoom.setCurrentFilter(filter);
                 unselectPanelButtons(mColorsPanelButtons);
                 mSharpenButton.setSelected(true);
-                mImageShow.showToast("Sharpen", true);
-                mImageShow.setCurrentFilter(null);
+                invalidateViews();
             }
         };
     }
diff --git a/src/com/android/gallery3d/filtershow/cache/ImageLoader.java b/src/com/android/gallery3d/filtershow/cache/ImageLoader.java
index ac16c13cd..9944f5fce 100644
--- a/src/com/android/gallery3d/filtershow/cache/ImageLoader.java
+++ b/src/com/android/gallery3d/filtershow/cache/ImageLoader.java
@@ -8,7 +8,9 @@ import android.database.Cursor;
 import android.database.sqlite.SQLiteException;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
+import android.graphics.BitmapRegionDecoder;
 import android.graphics.Matrix;
+import android.graphics.Rect;
 import android.media.ExifInterface;
 import android.net.Uri;
 import android.provider.MediaStore;
@@ -42,6 +44,7 @@ public class ImageLoader {
 
     private Cache mCache = new DelayedPresetCache(30);
     private Cache mHiresCache = new DelayedPresetCache(2);
+    private ZoomCache mZoomCache = new ZoomCache();
 
     private int mOrientation = 0;
     private HistoryAdapter mAdapter = null;
@@ -50,6 +53,8 @@ public class ImageLoader {
     private Context mContext = null;
     private Uri mUri = null;
 
+    private Rect mOriginalBounds = null;
+
     public ImageLoader(Context context) {
         mContext = context;
     }
@@ -66,6 +71,10 @@ public class ImageLoader {
         return mUri;
     }
 
+    public Rect getOriginalBounds() {
+        return mOriginalBounds;
+    }
+
     private int getOrientation(Uri uri) {
         if (ContentResolver.SCHEME_FILE.equals(uri.getScheme())) {
             return getOrientationFromPath(uri.getPath());
@@ -125,6 +134,22 @@ public class ImageLoader {
         }
     }
 
+    private Bitmap loadRegionBitmap(Uri uri, Rect bounds) {
+        InputStream is = null;
+        try {
+            is = mContext.getContentResolver().openInputStream(uri);
+            BitmapRegionDecoder decoder = BitmapRegionDecoder.newInstance(is, false);
+            return decoder.decodeRegion(bounds, null);
+        } catch (FileNotFoundException e) {
+            Log.e(LOGTAG, "FileNotFoundException: " + uri);
+        } catch (Exception e) {
+            e.printStackTrace();
+        } finally {
+            closeStream(is);
+        }
+        return null;
+    }
+
     private Bitmap loadScaledBitmap(Uri uri, int size) {
         InputStream is = null;
         try {
@@ -137,6 +162,9 @@ public class ImageLoader {
 
             int width_tmp = o.outWidth;
             int height_tmp = o.outHeight;
+
+            mOriginalBounds = new Rect(0, 0, width_tmp, height_tmp);
+
             int scale = 1;
             while (true) {
                 if (width_tmp / 2 < size || height_tmp / 2 < size)
@@ -192,6 +220,24 @@ public class ImageLoader {
         }
     }
 
+    // TODO: this currently does the loading + filtering on the UI thread -- need to
+    // move this to a background thread.
+    public Bitmap getScaleOneImageForPreset(ImageShow caller, ImagePreset imagePreset, Rect bounds,
+            boolean force) {
+        Bitmap bmp = mZoomCache.getImage(imagePreset, bounds);
+        if (force || bmp == null) {
+            bmp = loadRegionBitmap(mUri, bounds);
+            if (bmp != null) {
+                // TODO: this workaround for RS might not be needed ultimately
+                Bitmap bmp2 = bmp.copy(Bitmap.Config.ARGB_8888, true);
+                imagePreset.apply(bmp2);
+                mZoomCache.setImage(imagePreset, bounds, bmp2);
+                return bmp2;
+            }
+        }
+        return bmp;
+    }
+
     // Caching method
     public Bitmap getImageForPreset(ImageShow caller, ImagePreset imagePreset,
             boolean hiRes) {
@@ -223,6 +269,7 @@ public class ImageLoader {
     public void resetImageForPreset(ImagePreset imagePreset, ImageShow caller) {
         mHiresCache.reset(imagePreset);
         mCache.reset(imagePreset);
+        mZoomCache.reset(imagePreset);
     }
 
     public Uri saveImage(ImagePreset preset, final FilterShowActivity filterShowActivity,
diff --git a/src/com/android/gallery3d/filtershow/cache/ZoomCache.java b/src/com/android/gallery3d/filtershow/cache/ZoomCache.java
new file mode 100644
index 000000000..e6e7f14ce
--- /dev/null
+++ b/src/com/android/gallery3d/filtershow/cache/ZoomCache.java
@@ -0,0 +1,39 @@
+package com.android.gallery3d.filtershow.cache;
+
+import android.graphics.Bitmap;
+import android.graphics.Rect;
+
+import com.android.gallery3d.filtershow.presets.ImagePreset;
+
+public class ZoomCache {
+
+    private ImagePreset mImagePreset = null;
+    private Bitmap mBitmap = null;
+    private Rect mBounds = null;
+
+    // TODO: move the processing to a background thread...
+    public Bitmap getImage(ImagePreset preset, Rect bounds) {
+        if (mBounds != bounds) {
+            return null;
+        }
+        if (mImagePreset == null) {
+            return null;
+        }
+        if (!mImagePreset.same(preset)) {
+            return null;
+        }
+        return mBitmap;
+    }
+
+    public void setImage(ImagePreset preset, Rect bounds, Bitmap bitmap) {
+        mBitmap = bitmap;
+        mBounds = bounds;
+        mImagePreset = preset;
+    }
+
+    public void reset(ImagePreset imagePreset) {
+        if (imagePreset == mImagePreset) {
+            mBitmap = null;
+        }
+    }
+}
diff --git a/src/com/android/gallery3d/filtershow/filters/ImageFilter.java b/src/com/android/gallery3d/filtershow/filters/ImageFilter.java
index c2bd952f8..c039fce47 100644
--- a/src/com/android/gallery3d/filtershow/filters/ImageFilter.java
+++ b/src/com/android/gallery3d/filtershow/filters/ImageFilter.java
@@ -2,11 +2,13 @@
 package com.android.gallery3d.filtershow.filters;
 
 import android.graphics.Bitmap;
+import android.util.Log;
 
 public class ImageFilter implements Cloneable {
 
     protected int mParameter = 0;
     protected String mName = "Original";
+    private final String LOGTAG = "ImageFilter";
 
     @Override
     public ImageFilter clone() throws CloneNotSupportedException {
diff --git a/src/com/android/gallery3d/filtershow/filters/ImageFilterRS.java b/src/com/android/gallery3d/filtershow/filters/ImageFilterRS.java
new file mode 100644
index 000000000..ab2d304a4
--- /dev/null
+++ b/src/com/android/gallery3d/filtershow/filters/ImageFilterRS.java
@@ -0,0 +1,59 @@
+package com.android.gallery3d.filtershow.filters;
+
+import android.app.Activity;
+import android.graphics.Bitmap;
+import android.renderscript.Allocation;
+import android.renderscript.RenderScript;
+import android.util.Log;
+
+public class ImageFilterRS extends ImageFilter {
+    private final String LOGTAG = "ImageFilterRS";
+
+    private static RenderScript mRS = null;
+    protected static Allocation mInPixelsAllocation;
+    protected static Allocation mOutPixelsAllocation;
+    private static android.content.res.Resources mResources = null;
+
+    public void prepare(Bitmap bitmap) {
+        mInPixelsAllocation = Allocation.createFromBitmap(mRS, bitmap,
+                Allocation.MipmapControl.MIPMAP_NONE,
+                Allocation.USAGE_SCRIPT);
+        mOutPixelsAllocation = Allocation.createTyped(mRS, mInPixelsAllocation.getType());
+    }
+
+    public void createFilter(android.content.res.Resources res) {
+    }
+
+    public void runFilter() {
+    }
+
+    public void update(Bitmap bitmap) {
+        mOutPixelsAllocation.copyTo(bitmap);
+    }
+
+    public void apply(Bitmap bitmap) {
+        if (bitmap == null) {
+            return;
+        }
+        try {
+            prepare(bitmap);
+            createFilter(mResources);
+            runFilter();
+            update(bitmap);
+        } catch (android.renderscript.RSIllegalArgumentException e) {
+            Log.e(LOGTAG, "Illegal argument? " + e);
+        } catch (android.renderscript.RSRuntimeException e) {
+            Log.e(LOGTAG, "RS runtime exception ? " + e);
+        }
+    }
+
+    public static RenderScript getRenderScriptContext() {
+        return mRS;
+    }
+
+    public static void setRenderScriptContext(Activity context) {
+        mRS = RenderScript.create(context);
+        mResources = context.getResources();
+    }
+
+}
diff --git a/src/com/android/gallery3d/filtershow/filters/ImageFilterSharpen.java b/src/com/android/gallery3d/filtershow/filters/ImageFilterSharpen.java
new file mode 100644
index 000000000..3ec7b5f70
--- /dev/null
+++ b/src/com/android/gallery3d/filtershow/filters/ImageFilterSharpen.java
@@ -0,0 +1,52 @@
+
+package com.android.gallery3d.filtershow.filters;
+
+import android.graphics.Bitmap;
+import android.util.Log;
+import android.renderscript.Element;
+import android.renderscript.Script;
+import android.renderscript.ScriptC;
+
+import com.android.gallery3d.R;
+
+public class ImageFilterSharpen extends ImageFilterRS {
+
+    private static final String LOGTAG = "ImageFilterSharpen";
+    private ScriptC_convolve3x3 mScript;
+
+    public ImageFilterSharpen() {
+        mName = "Sharpen";
+    }
+
+    public void createFilter(android.content.res.Resources res) {
+        int w = mInPixelsAllocation.getType().getX();
+        int h = mInPixelsAllocation.getType().getY();
+
+        float p1 = mParameter;
+        float value = p1 / 100.0f;
+        float f[] = new float[9];
+        float p = value;
+        f[0] = -p;
+        f[1] = -p;
+        f[2] = -p;
+        f[3] = -p;
+        f[4] = 8 * p + 1;
+        f[5] = -p;
+        f[6] = -p;
+        f[7] = -p;
+        f[8] = -p;
+        if (mScript == null) {
+            mScript = new ScriptC_convolve3x3(getRenderScriptContext(), res, R.raw.convolve3x3);
+        }
+        mScript.set_gCoeffs(f);
+        mScript.set_gWidth(w);
+        mScript.set_gHeight(h);
+    }
+
+    public void runFilter() {
+        mScript.set_gIn(mInPixelsAllocation);
+        mScript.bind_gPixels(mInPixelsAllocation);
+        mScript.forEach_root(mInPixelsAllocation, mOutPixelsAllocation);
+    }
+
+}
diff --git a/src/com/android/gallery3d/filtershow/filters/convolve3x3.rs b/src/com/android/gallery3d/filtershow/filters/convolve3x3.rs
new file mode 100644
index 000000000..2acffab06
--- /dev/null
+++ b/src/com/android/gallery3d/filtershow/filters/convolve3x3.rs
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma version(1)
+#pragma rs java_package_name(com.android.gallery3d.filtershow.filters)
+#pragma rs_fp_relaxed
+
+int32_t gWidth;
+int32_t gHeight;
+const uchar4 *gPixels;
+rs_allocation gIn;
+
+float gCoeffs[9];
+
+void root(const uchar4 *in, uchar4 *out, const void *usrData, uint32_t x, uint32_t y) {
+    uint32_t x1 = min((int32_t)x+1, gWidth-1);
+    uint32_t x2 = max((int32_t)x-1, 0);
+    uint32_t y1 = min((int32_t)y+1, gHeight-1);
+    uint32_t y2 = max((int32_t)y-1, 0);
+
+    float4 p00 = rsUnpackColor8888(gPixels[x1 + gWidth * y1]);
+    float4 p01 = rsUnpackColor8888(gPixels[x + gWidth * y1]);
+    float4 p02 = rsUnpackColor8888(gPixels[x2 + gWidth * y1]);
+    float4 p10 = rsUnpackColor8888(gPixels[x1 + gWidth * y]);
+    float4 p11 = rsUnpackColor8888(gPixels[x + gWidth * y]);
+    float4 p12 = rsUnpackColor8888(gPixels[x2 + gWidth * y]);
+    float4 p20 = rsUnpackColor8888(gPixels[x1 + gWidth * y2]);
+    float4 p21 = rsUnpackColor8888(gPixels[x + gWidth * y2]);
+    float4 p22 = rsUnpackColor8888(gPixels[x2 + gWidth * y2]);
+
+    p00 *= gCoeffs[0];
+    p01 *= gCoeffs[1];
+    p02 *= gCoeffs[2];
+    p10 *= gCoeffs[3];
+    p11 *= gCoeffs[4];
+    p12 *= gCoeffs[5];
+    p20 *= gCoeffs[6];
+    p21 *= gCoeffs[7];
+    p22 *= gCoeffs[8];
+
+    p00 += p01;
+    p02 += p10;
+    p11 += p12;
+    p20 += p21;
+
+    p22 += p00;
+    p02 += p11;
+
+    p20 += p22;
+    p20 += p02;
+
+    p20 = clamp(p20, 0.f, 1.f);
+    *out = rsPackColorTo8888(p20.r, p20.g, p20.b);
+}
diff --git a/src/com/android/gallery3d/filtershow/imageshow/ImageBorder.java b/src/com/android/gallery3d/filtershow/imageshow/ImageBorder.java
index 00be8267d..f8c0142ae 100644
--- a/src/com/android/gallery3d/filtershow/imageshow/ImageBorder.java
+++ b/src/com/android/gallery3d/filtershow/imageshow/ImageBorder.java
@@ -13,9 +13,8 @@ import android.graphics.Rect;
 import android.graphics.drawable.NinePatchDrawable;
 import android.util.AttributeSet;
 
-public class ImageBorder extends ImageShow {
+public class ImageBorder extends ImageSlave {
     Paint gPaint = new Paint();
-    private ImageShow mMasterImageShow = null;
 
     public ImageBorder(Context context) {
         super(context);
@@ -25,18 +24,6 @@ public class ImageBorder extends ImageShow {
         super(context, attrs);
     }
 
-    public void setMaster(ImageShow master) {
-        mMasterImageShow = master;
-    }
-
-    public ImagePreset getImagePreset() {
-        return mMasterImageShow.getImagePreset();
-    }
-
-    public void setImagePreset(ImagePreset preset, boolean addToHistory) {
-        mMasterImageShow.setImagePreset(preset, addToHistory);
-    }
-
     public boolean showTitle() {
         return false;
     }
diff --git a/src/com/android/gallery3d/filtershow/imageshow/ImageShow.java b/src/com/android/gallery3d/filtershow/imageshow/ImageShow.java
index 2caa2d578..2a660d40f 100644
--- a/src/com/android/gallery3d/filtershow/imageshow/ImageShow.java
+++ b/src/com/android/gallery3d/filtershow/imageshow/ImageShow.java
@@ -61,19 +61,31 @@ public class ImageShow extends View implements SliderListener {
     private boolean mShowToast = false;
     private boolean mImportantToast = false;
 
+    protected float mTouchX = 0;
+    protected float mTouchY = 0;
+
     private Handler mHandler = new Handler();
 
     public void onNewValue(int value) {
-        if (mCurrentFilter != null) {
-            mCurrentFilter.setParameter(value);
+        if (getCurrentFilter() != null) {
+            getCurrentFilter().setParameter(value);
         }
-        if (mImagePreset != null) {
-            mImageLoader.resetImageForPreset(mImagePreset, this);
-            mImagePreset.fillImageStateAdapter(mImageStateAdapter);
+        if (getImagePreset() != null) {
+            mImageLoader.resetImageForPreset(getImagePreset(), this);
+            getImagePreset().fillImageStateAdapter(mImageStateAdapter);
         }
         invalidate();
     }
 
+    public void onTouchDown(float x, float y) {
+        mTouchX = x;
+        mTouchY = y;
+        invalidate();
+    }
+
+    public void onTouchUp() {
+    }
+
     public ImageShow(Context context, AttributeSet attrs) {
         super(context, attrs);
         mSliderController.setListener(this);
@@ -102,6 +114,10 @@ public class ImageShow extends View implements SliderListener {
         mCurrentFilter = filter;
     }
 
+    public ImageFilter getCurrentFilter() {
+        return mCurrentFilter;
+    }
+
     public void setAdapter(HistoryAdapter adapter) {
         mHistoryAdapter = adapter;
     }
@@ -125,6 +141,10 @@ public class ImageShow extends View implements SliderListener {
         }, 400);
     }
 
+    public Rect getImageBounds() {
+        return mImageBounds;
+    }
+
     public ImagePreset getImagePreset() {
         return mImagePreset;
     }
@@ -161,16 +181,32 @@ public class ImageShow extends View implements SliderListener {
     }
 
     public void onDraw(Canvas canvas) {
-        if (mBackgroundImage == null) {
-            mBackgroundImage = mImageLoader.getBackgroundBitmap(getResources());
+        drawBackground(canvas);
+        getFilteredImage();
+        drawImage(canvas, mFilteredImage);
+
+        if (showTitle() && getImagePreset() != null) {
+            mPaint.setARGB(200, 0, 0, 0);
+            mPaint.setTextSize(mTextSize);
+
+            Rect textRect = new Rect(0, 0, getWidth(), mTextSize + mTextPadding);
+            canvas.drawRect(textRect, mPaint);
+            mPaint.setARGB(255, 200, 200, 200);
+            canvas.drawText(getImagePreset().name(), mTextPadding,
+                    10 + mTextPadding, mPaint);
         }
-        if (mBackgroundImage != null) {
-            Rect s = new Rect(0, 0, mBackgroundImage.getWidth(),
-                    mBackgroundImage.getHeight());
-            Rect d = new Rect(0, 0, getWidth(), getHeight());
-            canvas.drawBitmap(mBackgroundImage, s, d, mPaint);
+        mPaint.setARGB(255, 150, 150, 150);
+        mPaint.setStrokeWidth(4);
+        canvas.drawLine(0, 0, getWidth(), 0, mPaint);
+
+        if (showControls()) {
+            mSliderController.onDraw(canvas);
         }
 
+        drawToast(canvas);
+    }
+
+    public void getFilteredImage() {
         Bitmap filteredImage = null;
         if (mImageLoader != null) {
             filteredImage = mImageLoader.getImageForPreset(this,
@@ -187,12 +223,14 @@ public class ImageShow extends View implements SliderListener {
         if (mShowOriginal || mFilteredImage == null) {
             mFilteredImage = mForegroundImage;
         }
+    }
 
-        if (mFilteredImage != null) {
-            Rect s = new Rect(0, 0, mFilteredImage.getWidth(),
-                    mFilteredImage.getHeight());
-            float ratio = mFilteredImage.getWidth()
-                    / (float) mFilteredImage.getHeight();
+    public void drawImage(Canvas canvas, Bitmap image) {
+        if (image != null) {
+            Rect s = new Rect(0, 0, image.getWidth(),
+                    image.getHeight());
+            float ratio = image.getWidth()
+                    / (float) image.getHeight();
             float w = getWidth();
             float h = w / ratio;
             float ty = (getHeight() - h) / 2.0f;
@@ -208,28 +246,20 @@ public class ImageShow extends View implements SliderListener {
                     (int) (h + ty));
             mImageBounds = d;
 
-            canvas.drawBitmap(mFilteredImage, s, d, mPaint);
+            canvas.drawBitmap(image, s, d, mPaint);
         }
+    }
 
-        if (showTitle() && getImagePreset() != null) {
-            mPaint.setARGB(200, 0, 0, 0);
-            mPaint.setTextSize(mTextSize);
-
-            Rect textRect = new Rect(0, 0, getWidth(), mTextSize + mTextPadding);
-            canvas.drawRect(textRect, mPaint);
-            mPaint.setARGB(255, 200, 200, 200);
-            canvas.drawText(getImagePreset().name(), mTextPadding,
-                    10 + mTextPadding, mPaint);
+    public void drawBackground(Canvas canvas) {
+        if (mBackgroundImage == null) {
+            mBackgroundImage = mImageLoader.getBackgroundBitmap(getResources());
         }
-        mPaint.setARGB(255, 150, 150, 150);
-        mPaint.setStrokeWidth(4);
-        canvas.drawLine(0, 0, getWidth(), 0, mPaint);
-
-        if (showControls()) {
-            mSliderController.onDraw(canvas);
+        if (mBackgroundImage != null) {
+            Rect s = new Rect(0, 0, mBackgroundImage.getWidth(),
+                    mBackgroundImage.getHeight());
+            Rect d = new Rect(0, 0, getWidth(), getHeight());
+            canvas.drawBitmap(mBackgroundImage, s, d, mPaint);
         }
-
-        drawToast(canvas);
     }
 
     public void setShowControls(boolean value) {
diff --git a/src/com/android/gallery3d/filtershow/imageshow/ImageSlave.java b/src/com/android/gallery3d/filtershow/imageshow/ImageSlave.java
new file mode 100644
index 000000000..debaec708
--- /dev/null
+++ b/src/com/android/gallery3d/filtershow/imageshow/ImageSlave.java
@@ -0,0 +1,65 @@
+package com.android.gallery3d.filtershow.imageshow;
+
+import android.content.Context;
+import android.graphics.Canvas;
+import android.util.AttributeSet;
+
+import com.android.gallery3d.filtershow.filters.ImageFilter;
+import com.android.gallery3d.filtershow.presets.ImagePreset;
+
+public class ImageSlave extends ImageShow {
+    private ImageShow mMasterImageShow = null;
+
+    public ImageSlave(Context context) {
+        super(context);
+    }
+
+    public ImageSlave(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public ImageShow getMaster() {
+        return mMasterImageShow;
+    }
+
+    public void setMaster(ImageShow master) {
+        mMasterImageShow = master;
+    }
+
+    public ImagePreset getImagePreset() {
+        return mMasterImageShow.getImagePreset();
+    }
+
+    public void setImagePreset(ImagePreset preset, boolean addToHistory) {
+        mMasterImageShow.setImagePreset(preset, addToHistory);
+    }
+
+    public void setCurrentFilter(ImageFilter filter) {
+        mMasterImageShow.setCurrentFilter(filter);
+    }
+
+    public ImageFilter getCurrentFilter() {
+        return mMasterImageShow.getCurrentFilter();
+    }
+
+    public void updateAngle() {
+        mMasterImageShow.setImageRotation(mImageRotation, mImageRotationZoomFactor);
+    }
+
+    public boolean showTitle() {
+        return false;
+    }
+
+    public float getImageRotation() {
+        return mMasterImageShow.getImageRotation();
+    }
+
+    public float getImageRotationZoomFactor() {
+        return mMasterImageShow.getImageRotationZoomFactor();
+    }
+
+    public void onDraw(Canvas canvas) {
+        super.onDraw(canvas);
+    }
+
+}
diff --git a/src/com/android/gallery3d/filtershow/imageshow/ImageStraighten.java b/src/com/android/gallery3d/filtershow/imageshow/ImageStraighten.java
index c4f0456cb..eb034bf10 100644
--- a/src/com/android/gallery3d/filtershow/imageshow/ImageStraighten.java
+++ b/src/com/android/gallery3d/filtershow/imageshow/ImageStraighten.java
@@ -15,8 +15,7 @@ import android.util.AttributeSet;
 import android.util.Log;
 import android.view.MotionEvent;
 
-public class ImageStraighten extends ImageShow {
-    private ImageShow mMasterImageShow = null;
+public class ImageStraighten extends ImageSlave {
     private float mImageRotation = 0;
     private float mImageRotationZoomFactor = 0;
 
@@ -48,26 +47,6 @@ public class ImageStraighten extends ImageShow {
         super(context, attrs);
     }
 
-    public void updateAngle() {
-        mMasterImageShow.setImageRotation(mImageRotation, mImageRotationZoomFactor);
-    }
-
-    public void setMaster(ImageShow master) {
-        mMasterImageShow = master;
-    }
-
-    public boolean showTitle() {
-        return false;
-    }
-
-    public ImagePreset getImagePreset() {
-        return mMasterImageShow.getImagePreset();
-    }
-
-    public void setImagePreset(ImagePreset preset, boolean addToHistory) {
-        mMasterImageShow.setImagePreset(preset, addToHistory);
-    }
-
     // ///////////////////////////////////////////////////////////////////////////
     // touch event handler
 
@@ -168,7 +147,7 @@ public class ImageStraighten extends ImageShow {
         // so that we can fake the rotation, etc.
         Bitmap image = null; // mMasterImageShow.mFilteredImage;
         if (image == null) {
-            image = mMasterImageShow.mForegroundImage;
+            image = getMaster().mForegroundImage;
         }
         if (image == null) {
             return;
diff --git a/src/com/android/gallery3d/filtershow/imageshow/ImageZoom.java b/src/com/android/gallery3d/filtershow/imageshow/ImageZoom.java
new file mode 100644
index 000000000..1c5a9b50e
--- /dev/null
+++ b/src/com/android/gallery3d/filtershow/imageshow/ImageZoom.java
@@ -0,0 +1,134 @@
+package com.android.gallery3d.filtershow.imageshow;
+
+import com.android.gallery3d.filtershow.presets.ImagePreset;
+
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.Rect;
+import android.util.AttributeSet;
+import android.view.GestureDetector;
+import android.view.GestureDetector.OnDoubleTapListener;
+import android.view.GestureDetector.OnGestureListener;
+import android.view.MotionEvent;
+
+public class ImageZoom extends ImageSlave implements OnGestureListener, OnDoubleTapListener {
+    private boolean mTouchDown = false;
+    private boolean mZoomedIn = false;
+    private Rect mZoomBounds = null;
+    private GestureDetector mGestureDetector = null;
+
+    public ImageZoom(Context context) {
+        super(context);
+        setupGestureDetector(context);
+    }
+
+    public ImageZoom(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        setupGestureDetector(context);
+    }
+
+    public void setupGestureDetector(Context context) {
+        mGestureDetector = new GestureDetector(context, this);
+    }
+
+    public boolean onTouchEvent(MotionEvent event) {
+        boolean ret = mGestureDetector.onTouchEvent(event);
+        ret = super.onTouchEvent(event);
+        return ret;
+    }
+
+    public void onTouchDown(float x, float y) {
+        super.onTouchDown(x, y);
+        if (mZoomedIn || mTouchDown) {
+            return;
+        }
+        mTouchDown = true;
+        Rect originalBounds = mImageLoader.getOriginalBounds();
+        Rect imageBounds = getImageBounds();
+        float touchX = x - imageBounds.left;
+        float touchY = y - imageBounds.top;
+
+        float w = originalBounds.width();
+        float h = originalBounds.height();
+        float ratio = w / h;
+        int mw = getWidth() / 2;
+        int mh = getHeight() / 2;
+        int cx = (int) (w / 2);
+        int cy = (int) (h / 2);
+        cx = (int) (touchX / imageBounds.width() * w);
+        cy = (int) (touchY / imageBounds.height() * h);
+        int left = cx - mw;
+        int top = cy - mh;
+        mZoomBounds = new Rect(left, top, left + mw * 2, top + mh * 2);
+    }
+
+    public void onTouchUp() {
+        mTouchDown = false;
+    }
+
+    public void onDraw(Canvas canvas) {
+        drawBackground(canvas);
+        Bitmap filteredImage = null;
+        if ((mZoomedIn ||mTouchDown) && mImageLoader != null) {
+            filteredImage = mImageLoader.getScaleOneImageForPreset(this, getImagePreset(), mZoomBounds, false);
+        } else {
+            getFilteredImage();
+            filteredImage = mFilteredImage;
+        }
+        drawImage(canvas, filteredImage);
+        if (showControls()) {
+            mSliderController.onDraw(canvas);
+        }
+
+        drawToast(canvas);
+    }
+
+    // TODO: move back some of that touch handling to a superclass / refactor
+    // SlideController into a more generic gesture detector
+    @Override
+    public boolean onDown(MotionEvent arg0) {
+        return false;
+    }
+
+    @Override
+    public boolean onFling(MotionEvent arg0, MotionEvent arg1, float arg2, float arg3) {
+        return false;
+    }
+
+    @Override
+    public void onLongPress(MotionEvent arg0) {
+    }
+
+    @Override
+    public boolean onScroll(MotionEvent arg0, MotionEvent arg1, float arg2, float arg3) {
+        return false;
+    }
+
+    @Override
+    public void onShowPress(MotionEvent arg0) {
+    }
+
+    @Override
+    public boolean onSingleTapUp(MotionEvent arg0) {
+        return false;
+    }
+
+    @Override
+    public boolean onSingleTapConfirmed(MotionEvent arg0) {
+        return false;
+    }
+
+    @Override
+    public boolean onDoubleTap(MotionEvent arg0) {
+        mZoomedIn = !mZoomedIn;
+        invalidate();
+        return false;
+    }
+
+    @Override
+    public boolean onDoubleTapEvent(MotionEvent arg0) {
+        return false;
+    }
+}
\ No newline at end of file
diff --git a/src/com/android/gallery3d/filtershow/ui/ImageCurves.java b/src/com/android/gallery3d/filtershow/ui/ImageCurves.java
index 8091c1e7b..3da058bc7 100644
--- a/src/com/android/gallery3d/filtershow/ui/ImageCurves.java
+++ b/src/com/android/gallery3d/filtershow/ui/ImageCurves.java
@@ -4,6 +4,7 @@ package com.android.gallery3d.filtershow.ui;
 import com.android.gallery3d.filtershow.filters.ImageFilter;
 import com.android.gallery3d.filtershow.filters.ImageFilterCurves;
 import com.android.gallery3d.filtershow.imageshow.ImageShow;
+import com.android.gallery3d.filtershow.imageshow.ImageSlave;
 import com.android.gallery3d.filtershow.presets.ImagePreset;
 import com.android.gallery3d.filtershow.ui.ControlPoint;
 import com.android.gallery3d.filtershow.ui.Spline;
@@ -22,7 +23,7 @@ import android.view.View;
 import android.widget.PopupMenu;
 import android.widget.Toast;
 
-public class ImageCurves extends ImageShow {
+public class ImageCurves extends ImageSlave {
 
     private static final String LOGTAG = "ImageCurves";
     Paint gPaint = new Paint();
@@ -31,7 +32,6 @@ public class ImageCurves extends ImageShow {
     float[] mAppliedCurve = new float[256];
     private boolean mDidAddPoint = false;
     private boolean mDidDelete = false;
-    private ImageShow mMasterImageShow = null;
     private ControlPoint mCurrentControlPoint = null;
     private boolean mUseRed = true;
     private boolean mUseGreen = true;
@@ -47,10 +47,6 @@ public class ImageCurves extends ImageShow {
         resetCurve();
     }
 
-    public void setMaster(ImageShow master) {
-        mMasterImageShow = master;
-    }
-
     public boolean showTitle() {
         return false;
     }
@@ -68,7 +64,7 @@ public class ImageCurves extends ImageShow {
     }
 
     public void reloadCurve() {
-        if (mMasterImageShow != null) {
+        if (getMaster() != null) {
             String filterName = getFilterName();
             ImageFilterCurves filter = (ImageFilterCurves) getImagePreset()
                     .getFilter(filterName);
@@ -86,27 +82,11 @@ public class ImageCurves extends ImageShow {
 
         mSpline.addPoint(0.0f, 1.0f);
         mSpline.addPoint(1.0f, 0.0f);
-        if (mMasterImageShow != null) {
+        if (getMaster() != null) {
             applyNewCurve();
         }
     }
 
-    public ImagePreset getImagePreset() {
-        return mMasterImageShow.getImagePreset();
-    }
-
-    public void setImagePreset(ImagePreset preset, boolean addToHistory) {
-        mMasterImageShow.setImagePreset(preset, addToHistory);
-    }
-
-    public float getImageRotation() {
-        return mMasterImageShow.getImageRotation();
-    }
-
-    public float getImageRotationZoomFactor() {
-        return mMasterImageShow.getImageRotationZoomFactor();
-    }
-
     public void onDraw(Canvas canvas) {
         super.onDraw(canvas);
 
diff --git a/src/com/android/gallery3d/filtershow/ui/SliderController.java b/src/com/android/gallery3d/filtershow/ui/SliderController.java
index b5b9c81ec..f2f0df30b 100644
--- a/src/com/android/gallery3d/filtershow/ui/SliderController.java
+++ b/src/com/android/gallery3d/filtershow/ui/SliderController.java
@@ -116,6 +116,9 @@ public class SliderController {
         mCurrentX = x;
         mCurrentY = y;
         mMode = MODES.DOWN;
+        if (mListener != null) {
+            mListener.onTouchDown(x, y);
+        }
     }
 
     public void setActionMove(float x, float y) {
@@ -131,6 +134,9 @@ public class SliderController {
     public void setActionUp() {
         mMode = MODES.UP;
         mOriginalValue = computeValue();
+        if (mListener != null) {
+            mListener.onTouchUp();
+        }
     }
 
     public void setNoAction() {
diff --git a/src/com/android/gallery3d/filtershow/ui/SliderListener.java b/src/com/android/gallery3d/filtershow/ui/SliderListener.java
index 67e28de0e..b11966ece 100644
--- a/src/com/android/gallery3d/filtershow/ui/SliderListener.java
+++ b/src/com/android/gallery3d/filtershow/ui/SliderListener.java
@@ -3,4 +3,6 @@ package com.android.gallery3d.filtershow.ui;
 
 public interface SliderListener {
     public void onNewValue(int value);
+    public void onTouchDown(float x, float y);
+    public void onTouchUp();
 }