1 /**************************************************************************
3 * Copyright 2009 Younes Manton.
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:
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
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.
26 **************************************************************************/
28 #include "util/u_math.h"
29 #include "util/u_debug.h"
34 * Color space conversion formulas
36 * To convert YCbCr to RGB,
41 * To calculate the color space conversion matrix csc with ProcAmp adjustments,
42 * mat44 csc, cstd, procamp, bias
43 * csc = cstd * (procamp * bias)
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)
49 * To calculate procamp,
50 * mat44 procamp, hue, saturation, brightness, contrast
51 * procamp = brightness * (saturation * (contrast * hue))
53 * procamp = saturation * (brightness * (contrast * hue))
75 * [ 0, cos(h), sin(h), 0]
76 * [ 0, -sin(h), cos(h), 0]
81 * [ 0, c*s*cos(h), c*s*sin(h), 0]
82 * [ 0, -c*s*sin(h), c*s*cos(h), 0]
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))]
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]
103 static const vl_csc_matrix bt_601
=
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
, }
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]
115 static const vl_csc_matrix bt_709
=
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
, }
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]
127 static const vl_csc_matrix smpte240m
=
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
, }
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
}
140 static const vl_csc_matrix identity
=
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
, }
147 const struct vl_procamp vl_default_procamp
= {
148 0.0f
, /* brightness */
150 1.0f
, /* saturation */
154 void vl_csc_get_matrix(enum VL_CSC_COLOR_STANDARD cs
,
155 struct vl_procamp
*procamp
,
157 vl_csc_matrix
*matrix
)
159 float cbbias
= -128.0f
/255.0f
;
160 float crbias
= -128.0f
/255.0f
;
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
;
169 const vl_csc_matrix
*cstd
;
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 */
177 /* Parameter substitutions */
184 case VL_CSC_COLOR_STANDARD_BT_601
:
187 case VL_CSC_COLOR_STANDARD_BT_709
:
190 case VL_CSC_COLOR_STANDARD_SMPTE_240M
:
193 case VL_CSC_COLOR_STANDARD_BT_709_REV
:
194 memcpy(matrix
, bt_709_rev
, sizeof(vl_csc_matrix
));
196 case VL_CSC_COLOR_STANDARD_IDENTITY
:
198 assert(cs
== VL_CSC_COLOR_STANDARD_IDENTITY
);
199 memcpy(matrix
, identity
, sizeof(vl_csc_matrix
));
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
);
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
);
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
);