Pillow

1
/*
2
 * The Python Imaging Library.
3
 * $Id$
4
 *
5
 * code to convert and unpack PhotoYCC data
6
 *
7
 * history:
8
 * 97-01-25 fl Moved from PcdDecode.c
9
 *
10
 * Copyright (c) Fredrik Lundh 1996-97.
11
 * Copyright (c) Secret Labs AB 1997.
12
 *
13
 * See the README file for information on usage and redistribution.
14
 */
15

16
#include "Imaging.h"
17

18
/* Tables generated by pcdtables.py, based on transforms taken from
19
   the "Colour Space Conversions FAQ" by Roberts/Ford. */
20

21
static INT16 L[] = {
22
    0,   1,   3,   4,   5,   7,   8,   10,  11,  12,  14,  15,  16,  18,  19,  20,
23
    22,  23,  24,  26,  27,  29,  30,  31,  33,  34,  35,  37,  38,  39,  41,  42,
24
    43,  45,  46,  48,  49,  50,  52,  53,  54,  56,  57,  58,  60,  61,  62,  64,
25
    65,  67,  68,  69,  71,  72,  73,  75,  76,  77,  79,  80,  82,  83,  84,  86,
26
    87,  88,  90,  91,  92,  94,  95,  96,  98,  99,  101, 102, 103, 105, 106, 107,
27
    109, 110, 111, 113, 114, 115, 117, 118, 120, 121, 122, 124, 125, 126, 128, 129,
28
    130, 132, 133, 134, 136, 137, 139, 140, 141, 143, 144, 145, 147, 148, 149, 151,
29
    152, 153, 155, 156, 158, 159, 160, 162, 163, 164, 166, 167, 168, 170, 171, 173,
30
    174, 175, 177, 178, 179, 181, 182, 183, 185, 186, 187, 189, 190, 192, 193, 194,
31
    196, 197, 198, 200, 201, 202, 204, 205, 206, 208, 209, 211, 212, 213, 215, 216,
32
    217, 219, 220, 221, 223, 224, 225, 227, 228, 230, 231, 232, 234, 235, 236, 238,
33
    239, 240, 242, 243, 245, 246, 247, 249, 250, 251, 253, 254, 255, 257, 258, 259,
34
    261, 262, 264, 265, 266, 268, 269, 270, 272, 273, 274, 276, 277, 278, 280, 281,
35
    283, 284, 285, 287, 288, 289, 291, 292, 293, 295, 296, 297, 299, 300, 302, 303,
36
    304, 306, 307, 308, 310, 311, 312, 314, 315, 317, 318, 319, 321, 322, 323, 325,
37
    326, 327, 329, 330, 331, 333, 334, 336, 337, 338, 340, 341, 342, 344, 345, 346
38
};
39

40
static INT16 CB[] = {
41
    -345, -343, -341, -338, -336, -334, -332, -329, -327, -325, -323, -321, -318, -316,
42
    -314, -312, -310, -307, -305, -303, -301, -298, -296, -294, -292, -290, -287, -285,
43
    -283, -281, -278, -276, -274, -272, -270, -267, -265, -263, -261, -258, -256, -254,
44
    -252, -250, -247, -245, -243, -241, -239, -236, -234, -232, -230, -227, -225, -223,
45
    -221, -219, -216, -214, -212, -210, -207, -205, -203, -201, -199, -196, -194, -192,
46
    -190, -188, -185, -183, -181, -179, -176, -174, -172, -170, -168, -165, -163, -161,
47
    -159, -156, -154, -152, -150, -148, -145, -143, -141, -139, -137, -134, -132, -130,
48
    -128, -125, -123, -121, -119, -117, -114, -112, -110, -108, -105, -103, -101, -99,
49
    -97,  -94,  -92,  -90,  -88,  -85,  -83,  -81,  -79,  -77,  -74,  -72,  -70,  -68,
50
    -66,  -63,  -61,  -59,  -57,  -54,  -52,  -50,  -48,  -46,  -43,  -41,  -39,  -37,
51
    -34,  -32,  -30,  -28,  -26,  -23,  -21,  -19,  -17,  -15,  -12,  -10,  -8,   -6,
52
    -3,   -1,   0,    2,    4,    7,    9,    11,   13,   16,   18,   20,   22,   24,
53
    27,   29,   31,   33,   35,   38,   40,   42,   44,   47,   49,   51,   53,   55,
54
    58,   60,   62,   64,   67,   69,   71,   73,   75,   78,   80,   82,   84,   86,
55
    89,   91,   93,   95,   98,   100,  102,  104,  106,  109,  111,  113,  115,  118,
56
    120,  122,  124,  126,  129,  131,  133,  135,  138,  140,  142,  144,  146,  149,
57
    151,  153,  155,  157,  160,  162,  164,  166,  169,  171,  173,  175,  177,  180,
58
    182,  184,  186,  189,  191,  193,  195,  197,  200,  202,  204,  206,  208,  211,
59
    213,  215,  217,  220
60
};
61

62
static INT16 GB[] = {
63
    67,  67,  66,  66,  65,  65,  65,  64,  64,  63,  63,  62,  62,  62,  61,  61,
64
    60,  60,  59,  59,  59,  58,  58,  57,  57,  56,  56,  56,  55,  55,  54,  54,
65
    53,  53,  52,  52,  52,  51,  51,  50,  50,  49,  49,  49,  48,  48,  47,  47,
66
    46,  46,  46,  45,  45,  44,  44,  43,  43,  43,  42,  42,  41,  41,  40,  40,
67
    40,  39,  39,  38,  38,  37,  37,  37,  36,  36,  35,  35,  34,  34,  34,  33,
68
    33,  32,  32,  31,  31,  31,  30,  30,  29,  29,  28,  28,  28,  27,  27,  26,
69
    26,  25,  25,  25,  24,  24,  23,  23,  22,  22,  22,  21,  21,  20,  20,  19,
70
    19,  19,  18,  18,  17,  17,  16,  16,  15,  15,  15,  14,  14,  13,  13,  12,
71
    12,  12,  11,  11,  10,  10,  9,   9,   9,   8,   8,   7,   7,   6,   6,   6,
72
    5,   5,   4,   4,   3,   3,   3,   2,   2,   1,   1,   0,   0,   0,   0,   0,
73
    -1,  -1,  -2,  -2,  -2,  -3,  -3,  -4,  -4,  -5,  -5,  -5,  -6,  -6,  -7,  -7,
74
    -8,  -8,  -8,  -9,  -9,  -10, -10, -11, -11, -11, -12, -12, -13, -13, -14, -14,
75
    -14, -15, -15, -16, -16, -17, -17, -18, -18, -18, -19, -19, -20, -20, -21, -21,
76
    -21, -22, -22, -23, -23, -24, -24, -24, -25, -25, -26, -26, -27, -27, -27, -28,
77
    -28, -29, -29, -30, -30, -30, -31, -31, -32, -32, -33, -33, -33, -34, -34, -35,
78
    -35, -36, -36, -36, -37, -37, -38, -38, -39, -39, -39, -40, -40, -41, -41, -42
79
};
80

81
static INT16 CR[] = {
82
    -249, -247, -245, -243, -241, -239, -238, -236, -234, -232, -230, -229, -227, -225,
83
    -223, -221, -219, -218, -216, -214, -212, -210, -208, -207, -205, -203, -201, -199,
84
    -198, -196, -194, -192, -190, -188, -187, -185, -183, -181, -179, -178, -176, -174,
85
    -172, -170, -168, -167, -165, -163, -161, -159, -157, -156, -154, -152, -150, -148,
86
    -147, -145, -143, -141, -139, -137, -136, -134, -132, -130, -128, -127, -125, -123,
87
    -121, -119, -117, -116, -114, -112, -110, -108, -106, -105, -103, -101, -99,  -97,
88
    -96,  -94,  -92,  -90,  -88,  -86,  -85,  -83,  -81,  -79,  -77,  -76,  -74,  -72,
89
    -70,  -68,  -66,  -65,  -63,  -61,  -59,  -57,  -55,  -54,  -52,  -50,  -48,  -46,
90
    -45,  -43,  -41,  -39,  -37,  -35,  -34,  -32,  -30,  -28,  -26,  -25,  -23,  -21,
91
    -19,  -17,  -15,  -14,  -12,  -10,  -8,   -6,   -4,   -3,   -1,   0,    2,    4,
92
    5,    7,    9,    11,   13,   15,   16,   18,   20,   22,   24,   26,   27,   29,
93
    31,   33,   35,   36,   38,   40,   42,   44,   46,   47,   49,   51,   53,   55,
94
    56,   58,   60,   62,   64,   66,   67,   69,   71,   73,   75,   77,   78,   80,
95
    82,   84,   86,   87,   89,   91,   93,   95,   97,   98,   100,  102,  104,  106,
96
    107,  109,  111,  113,  115,  117,  118,  120,  122,  124,  126,  128,  129,  131,
97
    133,  135,  137,  138,  140,  142,  144,  146,  148,  149,  151,  153,  155,  157,
98
    158,  160,  162,  164,  166,  168,  169,  171,  173,  175,  177,  179,  180,  182,
99
    184,  186,  188,  189,  191,  193,  195,  197,  199,  200,  202,  204,  206,  208,
100
    209,  211,  213,  215
101
};
102

103
static INT16 GR[] = {
104
    127, 126, 125, 124, 123, 122, 121,  121,  120,  119,  118,  117,  116,  115,  114,
105
    113, 112, 111, 110, 109, 108, 108,  107,  106,  105,  104,  103,  102,  101,  100,
106
    99,  98,  97,  96,  95,  95,  94,   93,   92,   91,   90,   89,   88,   87,   86,
107
    85,  84,  83,  83,  82,  81,  80,   79,   78,   77,   76,   75,   74,   73,   72,
108
    71,  70,  70,  69,  68,  67,  66,   65,   64,   63,   62,   61,   60,   59,   58,
109
    57,  57,  56,  55,  54,  53,  52,   51,   50,   49,   48,   47,   46,   45,   45,
110
    44,  43,  42,  41,  40,  39,  38,   37,   36,   35,   34,   33,   32,   32,   31,
111
    30,  29,  28,  27,  26,  25,  24,   23,   22,   21,   20,   19,   19,   18,   17,
112
    16,  15,  14,  13,  12,  11,  10,   9,    8,    7,    6,    6,    5,    4,    3,
113
    2,   1,   0,   0,   -1,  -2,  -3,   -4,   -5,   -5,   -6,   -7,   -8,   -9,   -10,
114
    -11, -12, -13, -14, -15, -16, -17,  -18,  -18,  -19,  -20,  -21,  -22,  -23,  -24,
115
    -25, -26, -27, -28, -29, -30, -31,  -31,  -32,  -33,  -34,  -35,  -36,  -37,  -38,
116
    -39, -40, -41, -42, -43, -44, -44,  -45,  -46,  -47,  -48,  -49,  -50,  -51,  -52,
117
    -53, -54, -55, -56, -56, -57, -58,  -59,  -60,  -61,  -62,  -63,  -64,  -65,  -66,
118
    -67, -68, -69, -69, -70, -71, -72,  -73,  -74,  -75,  -76,  -77,  -78,  -79,  -80,
119
    -81, -82, -82, -83, -84, -85, -86,  -87,  -88,  -89,  -90,  -91,  -92,  -93,  -94,
120
    -94, -95, -96, -97, -98, -99, -100, -101, -102, -103, -104, -105, -106, -107, -107,
121
    -108
122
};
123

124
#define R 0
125
#define G 1
126
#define B 2
127
#define A 3
128

129
#define YCC2RGB(rgb, y, cb, cr)                       \
130
    {                                                 \
131
        int l = L[y];                                 \
132
        int r = l + CR[cr];                           \
133
        int g = l + GR[cr] + GB[cb];                  \
134
        int b = l + CB[cb];                           \
135
        rgb[0] = (r <= 0) ? 0 : (r >= 255) ? 255 : r; \
136
        rgb[1] = (g <= 0) ? 0 : (g >= 255) ? 255 : g; \
137
        rgb[2] = (b <= 0) ? 0 : (b >= 255) ? 255 : b; \
138
    }
139

140
void
141
ImagingUnpackYCC(UINT8 *out, const UINT8 *in, int pixels) {
142
    int i;
143
    /* PhotoYCC triplets */
144
    for (i = 0; i < pixels; i++) {
145
        YCC2RGB(out, in[0], in[1], in[2]);
146
        out[A] = 255;
147
        out += 4;
148
        in += 3;
149
    }
150
}
151

152
void
153
ImagingUnpackYCCA(UINT8 *out, const UINT8 *in, int pixels) {
154
    int i;
155
    /* PhotoYCC triplets plus premultiplied alpha */
156
    for (i = 0; i < pixels; i++) {
157
        /* Divide by alpha */
158
        UINT8 rgb[3];
159
        rgb[0] = (in[3] == 0) ? 0 : (((int)in[0] * 255) / in[3]);
160
        rgb[1] = (in[3] == 0) ? 0 : (((int)in[1] * 255) / in[3]);
161
        rgb[2] = (in[3] == 0) ? 0 : (((int)in[2] * 255) / in[3]);
162
        /* Convert non-multiplied data to RGB */
163
        YCC2RGB(out, rgb[0], rgb[1], rgb[2]);
164
        out[A] = in[3];
165
        out += 4;
166
        in += 4;
167
    }
168
}
169