2 Copyright (C) 2012-2013 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.
20 #include "rec709_linearised_gamma_lut.h"
22 using namespace libdcp;
24 LUTCache<Rec709LinearisedGammaLUT> Rec709LinearisedGammaLUT::cache;
26 Rec709LinearisedGammaLUT::Rec709LinearisedGammaLUT (int bits, float gamma)
29 int const bit_length = pow (2, bits);
30 for (int i = 0; i < bit_length; ++i) {
31 float const p = static_cast<float> (i) / (bit_length - 1);
33 _lut[i] = pow ((p + 0.099) / 1.099, gamma);