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/*
Copyright (C) 2014 Carl Hetherington <cth@carlh.net>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "image.h"
#include "rgb_xyz.h"
#include "xyz_frame.h"
#include "colour_conversion.h"
#include <boost/test/unit_test.hpp>
using std::max;
using boost::shared_ptr;
class SimpleImage : public dcp::Image
{
public:
SimpleImage (dcp::Size size)
: Image (size)
{
/* 48bpp */
_stride[0] = _size.width * 6;
_data[0] = new uint16_t[size.height * stride()[0] / 2];
}
~SimpleImage ()
{
delete[] _data[0];
}
uint16_t * const * data () const {
return _data;
}
int const * stride () const {
return _stride;
}
private:
uint16_t* _data[1];
int _stride[1];
};
/** Convert a test image from sRGB to XYZ and check that the transforms are right */
BOOST_AUTO_TEST_CASE (rgb_xyz_test)
{
unsigned int seed = 0;
dcp::Size const size (640, 480);
shared_ptr<const dcp::Image> rgb (new SimpleImage (size));
for (int y = 0; y < size.height; ++y) {
uint16_t* p = rgb->data()[0] + y * rgb->stride()[0] / 2;
for (int x = 0; x < size.width; ++x) {
/* Write a 12-bit random number for each component */
for (int c = 0; c < 3; ++c) {
*p = (rand_r (&seed) & 0xfff) << 4;
++p;
}
}
}
shared_ptr<dcp::XYZFrame> xyz = dcp::rgb_to_xyz (rgb, dcp::ColourConversion::srgb_to_xyz);
for (int y = 0; y < size.height; ++y) {
uint16_t* p = rgb->data()[0] + y * rgb->stride()[0] / 2;
for (int x = 0; x < size.width; ++x) {
double cr = *p++ / 65535.0;
double cg = *p++ / 65535.0;
double cb = *p++ / 65535.0;
/* Input gamma */
if (cr < 0.04045) {
cr /= 12.92;
} else {
cr = pow ((cr + 0.055) / 1.055, 2.4);
}
if (cg < 0.04045) {
cg /= 12.92;
} else {
cg = pow ((cg + 0.055) / 1.055, 2.4);
}
if (cb < 0.04045) {
cb /= 12.92;
} else {
cb = pow ((cb + 0.055) / 1.055, 2.4);
}
/* Matrix */
double cx = cr * 0.4124564 + cg * 0.3575761 + cb * 0.1804375;
double cy = cr * 0.2126729 + cg * 0.7151522 + cb * 0.0721750;
double cz = cr * 0.0193339 + cg * 0.1191920 + cb * 0.9503041;
/* Compand */
cx *= 48 / 52.37;
cy *= 48 / 52.37;
cz *= 48 / 52.37;
/* Output gamma */
cx = pow (cx, 1 / 2.6);
cy = pow (cy, 1 / 2.6);
cz = pow (cz, 1 / 2.6);
BOOST_REQUIRE_CLOSE (cx * 4095, xyz->data(0)[y * size.width + x], 1);
BOOST_REQUIRE_CLOSE (cy * 4095, xyz->data(1)[y * size.width + x], 1);
BOOST_REQUIRE_CLOSE (cz * 4095, xyz->data(2)[y * size.width + x], 1);
}
}
}
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