Add contrast & brightness filters

Added hue fixed contrast
Stablized Contrast, Saturation, Tint, Exposure

bug:7234321
Change-Id: Iadd1e3ab215b60f920b718fa56611a07f24effee

1 files changed, 46 insertions, 0 deletions

diff --git a/jni/filters/contrast.c b/jni/filters/contrast.c
new file mode 100644
index 000000000..45209c1fb
--- /dev/null
+++ b/jni/filters/contrast.c
@@ -0,0 +1,46 @@
+/*
+ * 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.
+ */
+
+#include "filters.h"
+
+unsigned char clamp(int c)
+{
+    int N = 255;
+    c &= ~(c >> 31);
+    c -= N;
+    c &= (c >> 31);
+    c += N;
+    return  (unsigned char) c;
+}
+
+void JNIFUNCF(ImageFilterContrast, nativeApplyFilter, jobject bitmap, jint width, jint height, jfloat bright)
+{
+    char* destination = 0;
+    AndroidBitmap_lockPixels(env, bitmap, (void**) &destination);
+    unsigned char * rgb = (unsigned char * )destination;
+    int i;
+    int len = width * height * 4;
+    float m =  (float)pow(2, bright/100.);
+    float c =  127-m*127;
+
+    for (i = 0; i < len; i+=4) {
+        rgb[RED]   = clamp((int)(m*rgb[RED]+c));
+        rgb[GREEN] = clamp((int)(m*rgb[GREEN]+c));
+        rgb[BLUE]  = clamp((int)(m*rgb[BLUE]+c));
+    }
+    AndroidBitmap_unlockPixels(env, bitmap);
+}
+