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 ITU-R BT.709 YCbCr pixels to RGB pixels where:
124 * Y, Cb, and Cr are in [0,255]
125 * R, G, and B are in [16,235]
126 */
127 static const vl_csc_matrix bt_709_full =
128 {
129 { 0.859f, 0.0f, 1.352f, 0.0625f, },
130 { 0.859f, -0.161f, -0.402f, 0.0625f, },
131 { 0.859f, 1.594f, 0.0f, 0.0625f, }
132 };
133
134 /*
135 * Converts SMPTE 240M YCbCr pixels to RGB pixels where:
136 * Y is in [16,235], Cb and Cr are in [16,240]
137 * R, G, and B are in [16,235]
138 */
139 static const vl_csc_matrix smpte240m =
140 {
141 { 1.0f, 0.0f, 1.541f, 0.0f, },
142 { 1.0f, -0.221f, -0.466f, 0.0f, },
143 { 1.0f, 1.785f, 0.0f, 0.0f, }
144 };
145
146 static const vl_csc_matrix bt_709_rev = {
147 { 0.183f, 0.614f, 0.062f, 0.0625f},
148 {-0.101f, -0.338f, 0.439f, 0.5f },
149 { 0.439f, -0.399f, -0.040f, 0.5f }
150 };
151
152 static const vl_csc_matrix bt_709_rev_full = {
153 { 0.213f, 0.715f, 0.072f, 0.0f },
154 {-0.115f, -0.385f, 0.5f, 0.5f },
155 { 0.5f, -0.454f, -0.046f, 0.5f }
156 };
157
158 static const vl_csc_matrix identity =
159 {
160 { 1.0f, 0.0f, 0.0f, 0.0f, },
161 { 0.0f, 1.0f, 0.0f, 0.0f, },
162 { 0.0f, 0.0f, 1.0f, 0.0f, }
163 };
164
165 const struct vl_procamp vl_default_procamp = {
166 0.0f, /* brightness */
167 1.0f, /* contrast */
168 1.0f, /* saturation */
169 0.0f /* hue */
170 };
171
vl_csc_get_matrix(enum VL_CSC_COLOR_STANDARD cs,struct vl_procamp * procamp,bool full_range,vl_csc_matrix * matrix)172 void vl_csc_get_matrix(enum VL_CSC_COLOR_STANDARD cs,
173 struct vl_procamp *procamp,
174 bool full_range,
175 vl_csc_matrix *matrix)
176 {
177 float cbbias = -128.0f/255.0f;
178 float crbias = -128.0f/255.0f;
179
180 const struct vl_procamp *p = procamp ? procamp : &vl_default_procamp;
181 float c = p->contrast;
182 float s = p->saturation;
183 float b = p->brightness;
184 float h = p->hue;
185 float x, y;
186
187 const vl_csc_matrix *cstd;
188
189 if (full_range) {
190 c *= 1.164f; /* Adjust for the y range */
191 b *= 1.164f; /* Adjust for the y range */
192 b -= c * 16.0f / 255.0f; /* Adjust for the y bias */
193 }
194
195 /* Parameter substitutions */
196 x = c * s * cosf(h);
197 y = c * s * sinf(h);
198
199 assert(matrix);
200
201 switch (cs) {
202 case VL_CSC_COLOR_STANDARD_BT_601:
203 cstd = &bt_601;
204 break;
205 case VL_CSC_COLOR_STANDARD_BT_709:
206 cstd = &bt_709;
207 break;
208 case VL_CSC_COLOR_STANDARD_BT_709_FULL:
209 cstd = &bt_709_full;
210 break;
211 case VL_CSC_COLOR_STANDARD_SMPTE_240M:
212 cstd = &smpte240m;
213 break;
214 case VL_CSC_COLOR_STANDARD_BT_709_REV:
215 memcpy(matrix, full_range ? bt_709_rev_full : bt_709_rev, sizeof(vl_csc_matrix));
216 return;
217 case VL_CSC_COLOR_STANDARD_IDENTITY:
218 default:
219 assert(cs == VL_CSC_COLOR_STANDARD_IDENTITY);
220 memcpy(matrix, identity, sizeof(vl_csc_matrix));
221 return;
222 }
223
224 (*matrix)[0][0] = c * (*cstd)[0][0];
225 (*matrix)[0][1] = (*cstd)[0][1] * x - (*cstd)[0][2] * y;
226 (*matrix)[0][2] = (*cstd)[0][2] * x + (*cstd)[0][1] * y;
227 (*matrix)[0][3] = (*cstd)[0][3] + (*cstd)[0][0] * b +
228 (*cstd)[0][1] * (x * cbbias + y * crbias) +
229 (*cstd)[0][2] * (x * crbias - y * cbbias);
230
231 (*matrix)[1][0] = c * (*cstd)[1][0];
232 (*matrix)[1][1] = (*cstd)[1][1] * x - (*cstd)[1][2] * y;
233 (*matrix)[1][2] = (*cstd)[1][2] * x + (*cstd)[1][1] * y;
234 (*matrix)[1][3] = (*cstd)[1][3] + (*cstd)[1][0] * b +
235 (*cstd)[1][1] * (x * cbbias + y * crbias) +
236 (*cstd)[1][2] * (x * crbias - y * cbbias);
237
238 (*matrix)[2][0] = c * (*cstd)[2][0];
239 (*matrix)[2][1] = (*cstd)[2][1] * x - (*cstd)[2][2] * y;
240 (*matrix)[2][2] = (*cstd)[2][2] * x + (*cstd)[2][1] * y;
241 (*matrix)[2][3] = (*cstd)[2][3] + (*cstd)[2][0] * b +
242 (*cstd)[2][1] * (x * cbbias + y * crbias) +
243 (*cstd)[2][2] * (x * crbias - y * cbbias);
244 }
245