/*
- Copyright (C) 2012-2014 Carl Hetherington <cth@carlh.net>
+ Copyright (C) 2012-2021 Carl Hetherington <cth@carlh.net>
- This program is free software; you can redistribute it and/or modify
+ This file is part of libdcp.
+
+ libdcp 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,
+ libdcp 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.
+ along with libdcp. If not, see <http://www.gnu.org/licenses/>.
+
+ In addition, as a special exception, the copyright holders give
+ permission to link the code of portions of this program with the
+ OpenSSL library under certain conditions as described in each
+ individual source file, and distribute linked combinations
+ including the two.
+ You must obey the GNU General Public License in all respects
+ for all of the code used other than OpenSSL. If you modify
+ file(s) with this exception, you may extend this exception to your
+ version of the file(s), but you are not obligated to do so. If you
+ do not wish to do so, delete this exception statement from your
+ version. If you delete this exception statement from all source
+ files in the program, then also delete it here.
*/
+
/** @file src/modified_gamma_transfer_function.h
- * @brief ModifiedGammaTransferFunction class.
+ * @brief ModifiedGammaTransferFunction class
*/
+
#include "transfer_function.h"
+
namespace dcp {
-/** A transfer function which for an input x gives an output y where
+
+/** A transfer function which for an input x gives a linear output y where
*
* y = x / B for x <= threshold
* y = ((x + A) / (1 + A))^power for x > threshold
+ *
+ * The reverse transform is
+ *
+ * x = y * B for y <= threshold / B
+ * x = (1 + A) * y ^ (1 / power) - A for y > threshold / B
*/
class ModifiedGammaTransferFunction : public TransferFunction
{
return _B;
}
- bool about_equal (boost::shared_ptr<const TransferFunction>, double epsilon) const;
-
+ bool about_equal (std::shared_ptr<const TransferFunction>, double epsilon) const;
+
protected:
double * make_lut (int bit_depth, bool inverse) const;
-
+
private:
double _power;
double _threshold;
double _B;
};
+
}