1 /*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
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
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
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.
15 */
16
17 #include <math.h>
18 #include "filters.h"
19
JNIFUNCF(ImageFilterBwFilter,nativeApplyFilter,jobject bitmap,jint width,jint height,jint rw,jint gw,jint bw)20 void JNIFUNCF(ImageFilterBwFilter, nativeApplyFilter, jobject bitmap, jint width, jint height, jint rw, jint gw, jint bw)
21 {
22 char* destination = 0;
23 AndroidBitmap_lockPixels(env, bitmap, (void**) &destination);
24 unsigned char * rgb = (unsigned char * )destination;
25 float sr = rw;
26 float sg = gw;
27 float sb = bw;
28
29 float min = MIN(sg,sb);
30 min = MIN(sr,min);
31 float max = MAX(sg,sb);
32 max = MAX(sr,max);
33 float avg = (min+max)/2;
34 sb /= avg;
35 sg /= avg;
36 sr /= avg;
37 int i;
38 int len = width * height * 4;
39
40 for (i = 0; i < len; i+=4)
41 {
42 float r = sr *rgb[RED];
43 float g = sg *rgb[GREEN];
44 float b = sb *rgb[BLUE];
45 min = MIN(g,b);
46 min = MIN(r,min);
47 max = MAX(g,b);
48 max = MAX(r,max);
49 avg =(min+max)/2;
50 rgb[RED] = CLAMP(avg);
51 rgb[GREEN] = rgb[RED];
52 rgb[BLUE] = rgb[RED];
53 }
54 AndroidBitmap_unlockPixels(env, bitmap);
55 }
56