1 // ==========================================================
2 // XYZ to RGB TIFF conversion routines
3 //
4 // Design and implementation by
5 // - Herv� Drolon (drolon@infonie.fr)
6 //
7 // This file is part of FreeImage 3
8 //
9 // COVERED CODE IS PROVIDED UNDER THIS LICENSE ON AN "AS IS" BASIS, WITHOUT WARRANTY
10 // OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION, WARRANTIES
11 // THAT THE COVERED CODE IS FREE OF DEFECTS, MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE
12 // OR NON-INFRINGING. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE COVERED
13 // CODE IS WITH YOU. SHOULD ANY COVERED CODE PROVE DEFECTIVE IN ANY RESPECT, YOU (NOT
14 // THE INITIAL DEVELOPER OR ANY OTHER CONTRIBUTOR) ASSUME THE COST OF ANY NECESSARY
15 // SERVICING, REPAIR OR CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL
16 // PART OF THIS LICENSE. NO USE OF ANY COVERED CODE IS AUTHORIZED HEREUNDER EXCEPT UNDER
17 // THIS DISCLAIMER.
18 //
19 // Use at your own risk!
20 // ==========================================================
21
22 #include "FreeImage.h"
23 #include "Utilities.h"
24
tiff_ConvertLineXYZToRGB(BYTE * target,BYTE * source,double stonits,int width_in_pixels)25 void tiff_ConvertLineXYZToRGB(BYTE *target, BYTE *source, double stonits, int width_in_pixels) {
26 FIRGBF *rgbf = (FIRGBF*)target;
27 float *xyz = (float*)source;
28
29 for (int cols = 0; cols < width_in_pixels; cols++) {
30 // assume CCIR-709 primaries (matrix from tif_luv.c)
31 // LOG Luv XYZ (D65) -> sRGB (CIE Illuminant E)
32 rgbf->red = (float)( 2.690*xyz[0] + -1.276*xyz[1] + -0.414*xyz[2]);
33 rgbf->green = (float)(-1.022*xyz[0] + 1.978*xyz[1] + 0.044*xyz[2]);
34 rgbf->blue = (float)( 0.061*xyz[0] + -0.224*xyz[1] + 1.163*xyz[2]);
35
36 /*
37 if (stonits != 0.0) {
38 rgbf->red = (float)(rgbf->red * stonits);
39 rgbf->green = (float)(rgbf->green * stonits);
40 rgbf->blue = (float)(rgbf->blue * stonits);
41 }
42 */
43
44 rgbf++;
45 xyz += 3;
46 }
47 }
48
tiff_ConvertLineRGBToXYZ(BYTE * target,BYTE * source,int width_in_pixels)49 void tiff_ConvertLineRGBToXYZ(BYTE *target, BYTE *source, int width_in_pixels) {
50 FIRGBF *rgbf = (FIRGBF*)source;
51 float *xyz = (float*)target;
52
53 for (int cols = 0; cols < width_in_pixels; cols++) {
54 // assume CCIR-709 primaries, whitepoint x = 1/3 y = 1/3 (D_E)
55 // "The LogLuv Encoding for Full Gamut, High Dynamic Range Images" <G.Ward>
56 // sRGB ( CIE Illuminant E ) -> LOG Luv XYZ (D65)
57 xyz[0] = (float)(0.497*rgbf->red + 0.339*rgbf->green + 0.164*rgbf->blue);
58 xyz[1] = (float)(0.256*rgbf->red + 0.678*rgbf->green + 0.066*rgbf->blue);
59 xyz[2] = (float)(0.023*rgbf->red + 0.113*rgbf->green + 0.864*rgbf->blue);
60
61 rgbf++;
62 xyz += 3;
63 }
64 }
65
66