itu_h273 source code

1 module itu_h273;
2 
3 
4 /+
5 
6 nothrow @nogc:
7 
8 /// ColourPrimaries indicates the chromaticity coordinates 
9 /// of the source colour primaries as specified in Table 2
10 /// in terms of the CIE 1931 definition of x and y as
11 /// specified by ISO/CIE 11664-1.
12 
13 enum ColourPrimaries : ubyte;
14 
15 private struct PrimariesData
16 {
17     float x_green, y_green;
18     float x_blue, y_blue;
19     float x_red, y_red;
20     float x_white, y_white;
21 }
22 
23 private PrimariesData getColourPrimaries(ColourPrimaries cp,
24     out bool reserved,
25     out bool unspecified)
26 {
27     switch (cp)
28     {
29         case 0:
30         case 3:
31         case 13: .. case 21:
32         case 23: .. case 255:
33 
34             reserved = true;
35             return PrimariesData.init;
36 
37         case 2:
38             unspecified = true;
39             return PrimariesData.init;
40 
41         default:
42              return PRIMARIES[cp-1];
43     }
44 
45     
46 
47 }
48 
49 private static immutable PrimariesData[22] PRIMARIES = 
50 [
51     PrimariesData(0.300, 0.600, 0.150, 0.060, 
52                   0.640, 0.330, 0.3127, 0.3290), 
53     PrimariesData.init,
54     PrimariesData.init,
55     PrimariesData(0.210, 0.710, 0.140, 0.080, 
56                   0.670, 0.330, 0.3100, 0.3160),
57 
58     PrimariesData(0.290, 0.600, 0.150,  0.060, 
59                   0.640, 0.330, 0.3127, 0.3290),
60     PrimariesData(0.310, 0.595, 0.155,  0.070, 
61                   0.630, 0.340, 0.3127, 0.3290), // 6
62     PrimariesData(0.310, 0.595, 0.155,  0.070, 
63                   0.630, 0.340, 0.3127, 0.3290), // 7
64     PrimariesData(0.243, 0.692, 0.145,  0.049, 
65                   0.681, 0.319, 0.310,  0.316), // Generic film
66     PrimariesData(0.170, 0.797, 0.131,  0.046,  // 9
67                   0.708, 0.292, 0.3127, 0.3290),
68 
69     // CIE 1931 XYZ, in YZX order
70     PrimariesData(0.000, 1.000, 0.000,  0.000,  // SMPTE ST 428-1
71                   1.000, 0.000, 0.3333333f, 0.333333f),
72     PrimariesData(0.265, 0.690, 0.150,  0.060,
73                   0.680, 0.320, 0.314f, 0.351f),
74     PrimariesData(0.265, 0.690, 0.150,  0.060,
75                   0.680, 0.320, 0.3127f, 0.3290f), // 12
76     PrimariesData.init, // 13
77     PrimariesData.init, // 14
78     PrimariesData.init, // 15
79     PrimariesData.init, // 16
80     PrimariesData.init, // 17
81     PrimariesData.init, // 18
82     PrimariesData.init, // 19
83     PrimariesData.init, // 20
84     PrimariesData.init, // 21
85     PrimariesData(0.295, 0.605, 0.155,  0.077,
86                   0.680, 0.340, 0.3127f, 0.3290f)
87 ];
88 
89 alias TransferCharacteristics = ubyte;
90 
91 
92 double transferColor(double Lc, 
93                      TransferCharacteristics car,
94                      out bool reserved,
95                      out bool unspecified)
96 {
97     switch(car)
98     {
99         case 0:
100         case 3:
101         case 19: .. case 255:
102             reserved = true; 
103             break;
104 
105 
106 
107         case 1: 
108         case 6: 
109         case 14: 
110         case 15: 
111         {
112             double alpha = 1.099296826809442;
113             double beta = 0.018053968510807;
114             if (Lc < beta) return Lc * 4.5;          
115         }
116 
117         case 8:
118 
119 
120     }
121 
122 
123 }
124 +/