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 "ip.rsh" 18 #pragma rs_fp_relaxed 19 20 rs_allocation histogramValues; 21 static float3 scale; 22 23 static uchar4 estimateWhite() { 24 int min_r = -1, min_g = -1, min_b = -1; 25 int max_r = 0, max_g = 0, max_b = 0; 26 int sum_r = 0, sum_g = 0, sum_b = 0; 27 28 for (int i = 1; i < 255; i++) { 29 int3 hv = rsGetElementAt_int3(histogramValues, i); 30 int r = hv.r; 31 int g = hv.g; 32 int b = hv.b; 33 sum_r += r; 34 sum_g += g; 35 sum_b += b; 36 37 if (r>0){ 38 if (min_r < 0) min_r = i; 39 max_r = i; 40 } 41 if (g>0){ 42 if (min_g < 0) min_g = i; 43 max_g = i; 44 } 45 if (b>0){ 46 if (min_b < 0) min_b = i; 47 max_b = i; 48 } 49 } 50 51 int sum15r = 0, sum15g = 0, sum15b = 0; 52 int count15r = 0, count15g = 0, count15b = 0; 53 int tmp_r = 0, tmp_g = 0, tmp_b = 0; 54 55 for (int i = 254; i >0; i--) { 56 int3 hv = rsGetElementAt_int3(histogramValues, i); 57 int r = hv.r; 58 int g = hv.g; 59 int b = hv.b; 60 tmp_r += r; 61 tmp_g += g; 62 tmp_b += b; 63 64 if ((tmp_r > sum_r/20) && (tmp_r < sum_r/5)) { 65 sum15r += r*i; 66 count15r += r; 67 } 68 if ((tmp_g > sum_g/20) && (tmp_g < sum_g/5)) { 69 sum15g += g*i; 70 count15g += g; 71 } 72 if ((tmp_b > sum_b/20) && (tmp_b < sum_b/5)) { 73 sum15b += b*i; 74 count15b += b; 75 } 76 77 } 78 79 uchar4 out; 80 81 if ((count15r>0) && (count15g>0) && (count15b>0) ){ 82 out.r = sum15r/count15r; 83 out.g = sum15g/count15g; 84 out.b = sum15b/count15b; 85 }else { 86 out.r = out.g = out.b = 255; 87 } 88 89 return out; 90 91 } 92 93 void prepareWhiteBalance() { 94 uchar4 estimation = estimateWhite(); 95 int minimum = min(estimation.r, min(estimation.g, estimation.b)); 96 int maximum = max(estimation.r, max(estimation.g, estimation.b)); 97 float avg = (minimum + maximum) / 2.f; 98 99 scale.r = avg / estimation.r; 100 scale.g = avg / estimation.g; 101 scale.b = avg / estimation.b; 102 } 103 104 uchar4 RS_KERNEL whiteBalanceKernel(uchar4 in) { 105 float3 t = convert_float3(in.rgb); 106 t *= scale; 107 t = min(t, 255.f); 108 109 uchar4 out; 110 out.rgb = convert_uchar3(t); 111 out.a = 255; 112 return out; 113 } 114
