From 75788462338b1b4f464d075465da3cb372c40004 Mon Sep 17 00:00:00 2001 From: Carl Hetherington Date: Sat, 27 Dec 2014 20:02:16 +0000 Subject: Change colourspace handling round a bit: - move the essence of GammaLUT into TransferFunction and handle different bit depths more neatly - add ColourConversion to describe input gamma correction, colour transformation and then output gamma correction in one class. - add default ColourConversions for sRGB->XYZ, Rec709->XYZ and XYZ->RGB. --- src/modified_gamma_transfer_function.h | 62 ++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 src/modified_gamma_transfer_function.h (limited to 'src/modified_gamma_transfer_function.h') diff --git a/src/modified_gamma_transfer_function.h b/src/modified_gamma_transfer_function.h new file mode 100644 index 00000000..0c6a6b84 --- /dev/null +++ b/src/modified_gamma_transfer_function.h @@ -0,0 +1,62 @@ +/* + Copyright (C) 2012-2014 Carl Hetherington + + 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 "transfer_function.h" + +namespace dcp { + +/** A transfer function which for an input x gives an output y where + * + * y = x / B for x <= threshold + * y = ((x + A) / (1 + A))^power for x > threshold + */ +class ModifiedGammaTransferFunction : public TransferFunction +{ +public: + ModifiedGammaTransferFunction (float power, float threshold, float A, float B); + + float power () const { + return _power; + } + + float threshold () const { + return _threshold; + } + + float A () const { + return _A; + } + + float B () const { + return _B; + } + + bool about_equal (boost::shared_ptr, float epsilon) const; + +protected: + float * make_lut (int bit_depth) const; + +private: + float _power; + float _threshold; + float _A; + float _B; +}; + +} -- cgit v1.2.3