2 * Copyright (C) 2012 The Android Open Source Project
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
20 unsigned char clamp(int c)
27 return (unsigned char) c;
30 int clampMax(int c,int max)
39 void JNIFUNCF(ImageFilterContrast, nativeApplyFilter, jobject bitmap, jint width, jint height, jfloat bright)
41 char* destination = 0;
42 AndroidBitmap_lockPixels(env, bitmap, (void**) &destination);
43 unsigned char * rgb = (unsigned char * )destination;
45 int len = width * height * 4;
46 float m = (float)pow(2, bright/100.);
49 for (i = 0; i < len; i+=4) {
50 rgb[RED] = clamp((int)(m*rgb[RED]+c));
51 rgb[GREEN] = clamp((int)(m*rgb[GREEN]+c));
52 rgb[BLUE] = clamp((int)(m*rgb[BLUE]+c));
54 AndroidBitmap_unlockPixels(env, bitmap);