2 Copyright (C) 2013 Carl Hetherington <cth@carlh.net>
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 #include "argb_frame.h"
22 #include "xyz_frame.h"
23 #include "gamma_lut.h"
27 using boost::shared_ptr;
28 using namespace libdcp;
30 /** Convert an openjpeg XYZ image to RGB.
31 * @param xyz_frame Frame in XYZ.
35 libdcp::xyz_to_rgb (shared_ptr<const XYZFrame> xyz_frame, shared_ptr<const GammaLUT> lut_in, shared_ptr<const GammaLUT> lut_out)
37 float const dci_coefficient = 48.0 / 52.37;
39 /* sRGB color matrix for XYZ -> RGB. This is the same as the one used by the Fraunhofer
40 EasyDCP player, I think.
43 float const colour_matrix[3][3] = {
44 { 3.24096989631653, -1.5373831987381, -0.498610764741898 },
45 { -0.96924364566803, 1.87596750259399, 0.0415550582110882 },
46 { 0.0556300804018974, -0.203976958990097, 1.05697154998779 }
49 int const max_colour = pow (2, lut_out->bit_depth()) - 1;
59 int* xyz_x = xyz_frame->data (0);
60 int* xyz_y = xyz_frame->data (1);
61 int* xyz_z = xyz_frame->data (2);
63 shared_ptr<ARGBFrame> argb_frame (new ARGBFrame (xyz_frame->size ()));
65 uint8_t* argb = argb_frame->data ();
67 for (int y = 0; y < xyz_frame->size().height; ++y) {
68 uint8_t* argb_line = argb;
69 for (int x = 0; x < xyz_frame->size().width; ++x) {
71 assert (*xyz_x >= 0 && *xyz_y >= 0 && *xyz_z >= 0 && *xyz_x < 4096 && *xyz_x < 4096 && *xyz_z < 4096);
74 s.x = lut_in->lut()[*xyz_x++];
75 s.y = lut_in->lut()[*xyz_y++];
76 s.z = lut_in->lut()[*xyz_z++];
79 s.x /= dci_coefficient;
80 s.y /= dci_coefficient;
81 s.z /= dci_coefficient;
84 d.r = ((s.x * colour_matrix[0][0]) + (s.y * colour_matrix[0][1]) + (s.z * colour_matrix[0][2]));
85 d.g = ((s.x * colour_matrix[1][0]) + (s.y * colour_matrix[1][1]) + (s.z * colour_matrix[1][2]));
86 d.b = ((s.x * colour_matrix[2][0]) + (s.y * colour_matrix[2][1]) + (s.z * colour_matrix[2][2]));
98 *argb_line++ = lut_out->lut()[(int) (d.b * max_colour)] * 0xff;
99 *argb_line++ = lut_out->lut()[(int) (d.g * max_colour)] * 0xff;
100 *argb_line++ = lut_out->lut()[(int) (d.r * max_colour)] * 0xff;
104 argb += argb_frame->stride ();