/*
* FlexiPix library
* !version: 1.0.0! !date: 2010-07-31!
*
* Copyright 2010 Stefan Schuermans <stefan schuermans info>
*
* 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, version 3 of the License.
*
*
* 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 Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <math.h>
#include <flexipix/types.h>
#include <intern/mapping.h>
#include <intern/types.h>
/**
* \brief precalculate mapping table
*
* updates the internal lookup table according to the parameters
*
* \param[in,out] p_mapping mapping to precalculate
*/
void flp_mapping_precalc(flp_mapping_t *p_mapping)
{
double gamma_1;
int v;
/* precalculate 1 / gamma */
gamma_1 = 1.0 / p_mapping->gamma;
/* map all values */
for (v = 0; v < 256; v++) {
double val = p_mapping->base
+ p_mapping->factor * pow((double)v / 255.0, gamma_1);
if (val < 0.0)
p_mapping->table[v] = 0;
else if (val > 1.0)
p_mapping->table[v] = 255;
else
p_mapping->table[v] = (flp_u8_t)(val * 255.0 + 0.5);
