1 /************************************************************************** 2 * 3 * Copyright 2009 Younes Manton. 4 * All Rights Reserved. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the 8 * "Software"), to deal in the Software without restriction, including 9 * without limitation the rights to use, copy, modify, merge, publish, 10 * distribute, sub license, and/or sell copies of the Software, and to 11 * permit persons to whom the Software is furnished to do so, subject to 12 * the following conditions: 13 * 14 * The above copyright notice and this permission notice (including the 15 * next paragraph) shall be included in all copies or substantial portions 16 * of the Software. 17 * 18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. 21 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR 22 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 23 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE 24 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 25 * 26 **************************************************************************/ 27 28 #include "util/u_math.h" 29 #include "util/u_debug.h" 30 31 #include "vl_csc.h" 32 33 /* 34 * Color space conversion formulas 35 * 36 * To convert YCbCr to RGB, 37 * vec4 ycbcr, rgb 38 * mat44 csc 39 * rgb = csc * ycbcr 40 * 41 * To calculate the color space conversion matrix csc with ProcAmp adjustments, 42 * mat44 csc, cstd, procamp, bias 43 * csc = cstd * (procamp * bias) 44 * 45 * Where cstd is a matrix corresponding to one of the color standards (BT.601, BT.709, etc) 46 * adjusted for the kind of YCbCr -> RGB mapping wanted (1:1, full), 47 * bias is a matrix corresponding to the kind of YCbCr -> RGB mapping wanted (1:1, full) 48 * 49 * To calculate procamp, 50 * mat44 procamp, hue, saturation, brightness, contrast 51 * procamp = brightness * (saturation * (contrast * hue)) 52 * Alternatively, 53 * procamp = saturation * (brightness * (contrast * hue)) 54 * 55 * contrast 56 * [ c, 0, 0, 0] 57 * [ 0, c, 0, 0] 58 * [ 0, 0, c, 0] 59 * [ 0, 0, 0, 1] 60 * 61 * brightness 62 * [ 1, 0, 0, b/c] 63 * [ 0, 1, 0, 0] 64 * [ 0, 0, 1, 0] 65 * [ 0, 0, 0, 1] 66 * 67 * saturation 68 * [ 1, 0, 0, 0] 69 * [ 0, s, 0, 0] 70 * [ 0, 0, s, 0] 71 * [ 0, 0, 0, 1] 72 * 73 * hue 74 * [ 1, 0, 0, 0] 75 * [ 0, cos(h), sin(h), 0] 76 * [ 0, -sin(h), cos(h), 0] 77 * [ 0, 0, 0, 1] 78 * 79 * procamp 80 * [ c, 0, 0, b] 81 * [ 0, c*s*cos(h), c*s*sin(h), 0] 82 * [ 0, -c*s*sin(h), c*s*cos(h), 0] 83 * [ 0, 0, 0, 1] 84 * 85 * bias 86 * [ 1, 0, 0, ybias] 87 * [ 0, 1, 0, cbbias] 88 * [ 0, 0, 1, crbias] 89 * [ 0, 0, 0, 1] 90 * 91 * csc 92 * [ c*cstd[ 0], c*cstd[ 1]*s*cos(h) - c*cstd[ 2]*s*sin(h), c*cstd[ 2]*s*cos(h) + c*cstd[ 1]*s*sin(h), cstd[ 3] + cstd[ 0]*(b + c*ybias) + cstd[ 1]*(c*cbbias*s*cos(h) + c*crbias*s*sin(h)) + cstd[ 2]*(c*crbias*s*cos(h) - c*cbbias*s*sin(h))] 93 * [ c*cstd[ 4], c*cstd[ 5]*s*cos(h) - c*cstd[ 6]*s*sin(h), c*cstd[ 6]*s*cos(h) + c*cstd[ 5]*s*sin(h), cstd[ 7] + cstd[ 4]*(b + c*ybias) + cstd[ 5]*(c*cbbias*s*cos(h) + c*crbias*s*sin(h)) + cstd[ 6]*(c*crbias*s*cos(h) - c*cbbias*s*sin(h))] 94 * [ c*cstd[ 8], c*cstd[ 9]*s*cos(h) - c*cstd[10]*s*sin(h), c*cstd[10]*s*cos(h) + c*cstd[ 9]*s*sin(h), cstd[11] + cstd[ 8]*(b + c*ybias) + cstd[ 9]*(c*cbbias*s*cos(h) + c*crbias*s*sin(h)) + cstd[10]*(c*crbias*s*cos(h) - c*cbbias*s*sin(h))] 95 * [ c*cstd[12], c*cstd[13]*s*cos(h) - c*cstd[14]*s*sin(h), c*cstd[14]*s*cos(h) + c*cstd[13]*s*sin(h), cstd[15] + cstd[12]*(b + c*ybias) + cstd[13]*(c*cbbias*s*cos(h) + c*crbias*s*sin(h)) + cstd[14]*(c*crbias*s*cos(h) - c*cbbias*s*sin(h))] 96 */ 97 98 /* 99 * Converts ITU-R BT.601 YCbCr pixels to RGB pixels where: 100 * Y is in [16,235], Cb and Cr are in [16,240] 101 * R, G, and B are in [16,235] 102 */ 103 static const vl_csc_matrix bt_601 = 104 { 105 { 1.0f, 0.0f, 1.371f, 0.0f, }, 106 { 1.0f, -0.336f, -0.698f, 0.0f, }, 107 { 1.0f, 1.732f, 0.0f, 0.0f, } 108 }; 109 110 /* 111 * Converts ITU-R BT.709 YCbCr pixels to RGB pixels where: 112 * Y is in [16,235], Cb and Cr are in [16,240] 113 * R, G, and B are in [16,235] 114 */ 115 static const vl_csc_matrix bt_709 = 116 { 117 { 1.0f, 0.0f, 1.540f, 0.0f, }, 118 { 1.0f, -0.183f, -0.459f, 0.0f, }, 119 { 1.0f, 1.816f, 0.0f, 0.0f, } 120 }; 121 122 /* 123 * Converts SMPTE 240M YCbCr pixels to RGB pixels where: 124 * Y is in [16,235], Cb and Cr are in [16,240] 125 * R, G, and B are in [16,235] 126 */ 127 static const vl_csc_matrix smpte240m = 128 { 129 { 1.0f, 0.0f, 1.541f, 0.0f, }, 130 { 1.0f, -0.221f, -0.466f, 0.0f, }, 131 { 1.0f, 1.785f, 0.0f, 0.0f, } 132 }; 133 134 static const vl_csc_matrix bt_709_rev = { 135 { 0.183f, 0.614f, 0.062f, 0.0625f}, 136 {-0.101f, -0.338f, 0.439f, 0.5f }, 137 { 0.439f, -0.399f, -0.040f, 0.5f } 138 }; 139 140 static const vl_csc_matrix identity = 141 { 142 { 1.0f, 0.0f, 0.0f, 0.0f, }, 143 { 0.0f, 1.0f, 0.0f, 0.0f, }, 144 { 0.0f, 0.0f, 1.0f, 0.0f, } 145 }; 146 147 const struct vl_procamp vl_default_procamp = { 148 0.0f, /* brightness */ 149 1.0f, /* contrast */ 150 1.0f, /* saturation */ 151 0.0f /* hue */ 152 }; 153 154 void vl_csc_get_matrix(enum VL_CSC_COLOR_STANDARD cs, 155 struct vl_procamp *procamp, 156 bool full_range, 157 vl_csc_matrix *matrix) 158 { 159 float cbbias = -128.0f/255.0f; 160 float crbias = -128.0f/255.0f; 161 162 const struct vl_procamp *p = procamp ? procamp : &vl_default_procamp; 163 float c = p->contrast; 164 float s = p->saturation; 165 float b = p->brightness; 166 float h = p->hue; 167 float x, y; 168 169 const vl_csc_matrix *cstd; 170 171 if (full_range) { 172 c *= 1.164f; /* Adjust for the y range */ 173 b *= 1.164f; /* Adjust for the y range */ 174 b -= c * 16.0f / 255.0f; /* Adjust for the y bias */ 175 } 176 177 /* Parameter substitutions */ 178 x = c * s * cosf(h); 179 y = c * s * sinf(h); 180 181 assert(matrix); 182 183 switch (cs) { 184 case VL_CSC_COLOR_STANDARD_BT_601: 185 cstd = &bt_601; 186 break; 187 case VL_CSC_COLOR_STANDARD_BT_709: 188 cstd = &bt_709; 189 break; 190 case VL_CSC_COLOR_STANDARD_SMPTE_240M: 191 cstd = &smpte240m; 192 break; 193 case VL_CSC_COLOR_STANDARD_BT_709_REV: 194 memcpy(matrix, bt_709_rev, sizeof(vl_csc_matrix)); 195 return; 196 case VL_CSC_COLOR_STANDARD_IDENTITY: 197 default: 198 assert(cs == VL_CSC_COLOR_STANDARD_IDENTITY); 199 memcpy(matrix, identity, sizeof(vl_csc_matrix)); 200 return; 201 } 202 203 (*matrix)[0][0] = c * (*cstd)[0][0]; 204 (*matrix)[0][1] = (*cstd)[0][1] * x - (*cstd)[0][2] * y; 205 (*matrix)[0][2] = (*cstd)[0][2] * x + (*cstd)[0][1] * y; 206 (*matrix)[0][3] = (*cstd)[0][3] + (*cstd)[0][0] * b + 207 (*cstd)[0][1] * (x * cbbias + y * crbias) + 208 (*cstd)[0][2] * (x * crbias - y * cbbias); 209 210 (*matrix)[1][0] = c * (*cstd)[1][0]; 211 (*matrix)[1][1] = (*cstd)[1][1] * x - (*cstd)[1][2] * y; 212 (*matrix)[1][2] = (*cstd)[1][2] * x + (*cstd)[1][1] * y; 213 (*matrix)[1][3] = (*cstd)[1][3] + (*cstd)[1][0] * b + 214 (*cstd)[1][1] * (x * cbbias + y * crbias) + 215 (*cstd)[1][2] * (x * crbias - y * cbbias); 216 217 (*matrix)[2][0] = c * (*cstd)[2][0]; 218 (*matrix)[2][1] = (*cstd)[2][1] * x - (*cstd)[2][2] * y; 219 (*matrix)[2][2] = (*cstd)[2][2] * x + (*cstd)[2][1] * y; 220 (*matrix)[2][3] = (*cstd)[2][3] + (*cstd)[2][0] * b + 221 (*cstd)[2][1] * (x * cbbias + y * crbias) + 222 (*cstd)[2][2] * (x * crbias - y * cbbias); 223 } 224
