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