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 20 double fastevalPoly(double *poly,int n, double x){ 21 22 double f =x; 23 double sum = poly[0]+poly[1]*f; 24 int i; 25 for (i = 2; i < n; i++) { 26 f*=x; 27 sum += poly[i]*f; 28 } 29 return sum; 30 } 31 32 void rgb2hsv( unsigned char *rgb,int rgbOff,unsigned short *hsv,int hsvOff) 33 { 34 int iMin,iMax,chroma; 35 int ABITS = 4; 36 int HSCALE = 256; 37 38 int k1=255 << ABITS; 39 int k2=HSCALE << ABITS; 40 41 int ri = rgb[rgbOff+0]; 42 int gi = rgb[rgbOff+1]; 43 int bi = rgb[rgbOff+2]; 44 short rv,rs,rh; 45 46 if (ri > gi) { 47 iMax = MAX (ri, bi); 48 iMin = MIN (gi, bi); 49 } else { 50 iMax = MAX (gi, bi); 51 iMin = MIN (ri, bi); 52 } 53 54 chroma = iMax - iMin; 55 // set value 56 rv = (short)( iMax << ABITS); 57 58 // set saturation 59 if (rv == 0) 60 rs = 0; 61 else 62 rs = (short)((k1*chroma)/iMax); 63 64 // set hue 65 if (rs == 0) 66 rh = 0; 67 else { 68 if ( ri == iMax ) { 69 rh = (short)( (k2*(6*chroma+gi - bi))/(6*chroma)); 70 if (rh >= k2) rh -= k2; 71 } else if (gi == iMax) 72 rh = (short)( (k2*(2*chroma+bi - ri ))/(6*chroma)); 73 else // (bi == iMax ) 74 rh = (short)( (k2*(4*chroma+ri - gi ))/(6*chroma)); 75 } 76 hsv[hsvOff+0] = rv; 77 hsv[hsvOff+1] = rs; 78 hsv[hsvOff+2] = rh; 79 } 80 81 void hsv2rgb(unsigned short *hsv,int hsvOff, unsigned char *rgb,int rgbOff) 82 { 83 int ABITS = 4; 84 int HSCALE = 256; 85 int m; 86 int H,X,ih,is,iv; 87 int k1=255<<ABITS; 88 int k2=HSCALE<<ABITS; 89 int k3=1<<(ABITS-1); 90 int rr=0; 91 int rg=0; 92 int rb=0; 93 short cv = hsv[hsvOff+0]; 94 short cs = hsv[hsvOff+1]; 95 short ch = hsv[hsvOff+2]; 96 97 // set chroma and min component value m 98 //chroma = ( cv * cs )/k1; 99 //m = cv - chroma; 100 m = ((int)cv*(k1 - (int)cs ))/k1; 101 102 // chroma == 0 <-> cs == 0 --> m=cv 103 if (cs == 0) { 104 rb = ( rg = ( rr =( cv >> ABITS) )); 105 } else { 106 ih=(int)ch; 107 is=(int)cs; 108 iv=(int)cv; 109 110 H = (6*ih)/k2; 111 X = ((iv*is)/k2)*(k2- abs(6*ih- 2*(H>>1)*k2 - k2)) ; 112 113 // removing additional bits --> unit8 114 X=( (X+iv*(k1 - is ))/k1 + k3 ) >> ABITS; 115 m=m >> ABITS; 116 117 // ( chroma + m ) --> cv ; 118 cv=(short) (cv >> ABITS); 119 switch (H) { 120 case 0: 121 rr = cv; 122 rg = X; 123 rb = m; 124 break; 125 case 1: 126 rr = X; 127 rg = cv; 128 rb = m; 129 break; 130 case 2: 131 rr = m; 132 rg = cv; 133 rb = X; 134 break; 135 case 3: 136 rr = m; 137 rg = X; 138 rb = cv; 139 break; 140 case 4: 141 rr = X; 142 rg = m; 143 rb = cv; 144 break; 145 case 5: 146 rr = cv; 147 rg = m ; 148 rb = X; 149 break; 150 } 151 } 152 rgb[rgbOff+0] = rr; 153 rgb[rgbOff+1] = rg; 154 rgb[rgbOff+2] = rb; 155 } 156 157
