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/**
* @file alg_ccm.h
* @brief color correction algorithm definition
* @author Patrick Roth - roth@stettbacher.ch
* @copyright Stettbacher Signal Processing AG
*
* @remarks
*
* <PRE>
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
* </PRE>
*
*/
/*
* This code inplements color correction algorithm and is pixel size independent. Including this code at the
* C-Source file will define the pixel-bit-depth (see color.c).
*/
// static void rgb_color_correction8(uint8_t *img_calib, const uint8_t *img_uncalib, const int color_bit_depth, const int height, const int width, float a[3][3])
// static void rgb_color_correction16(uint16_t *img_calib, const uint16_t *img_uncalib, const int color_bit_depth, const int height, const int width, float a[3][3])
{
int y, x;
int uncal_red, uncal_green, uncal_blue;
int cal_red, cal_green, cal_blue;
int index;
int pix_max_val;
const int shift_fact = 16;
const int a11 = (int) (a[0][0]*(1<<shift_fact));
const int a12 = (int) (a[0][1]*(1<<shift_fact));
const int a13 = (int) (a[0][2]*(1<<shift_fact));
const int a21 = (int) (a[1][0]*(1<<shift_fact));
const int a22 = (int) (a[1][1]*(1<<shift_fact));
const int a23 = (int) (a[1][2]*(1<<shift_fact));
const int a31 = (int) (a[2][0]*(1<<shift_fact));
const int a32 = (int) (a[2][1]*(1<<shift_fact));
const int a33 = (int) (a[2][2]*(1<<shift_fact));
index = 0;
pix_max_val = (1<<color_bit_depth)-1;
for(y = 0; y < height; y++) {
for(x = 0; x < width; x++) {
uncal_red = img_uncalib[index];
uncal_green = img_uncalib[index+1];
uncal_blue = img_uncalib[index+2];
// apply color correction matrix
cal_red = (uncal_red*a11 + uncal_green*a12 + uncal_blue*a13) >> shift_fact;
cal_green = (uncal_red*a21 + uncal_green*a22 + uncal_blue*a23) >> shift_fact;
cal_blue = (uncal_red*a31 + uncal_green*a32 + uncal_blue*a33) >> shift_fact;
// range check
if(cal_red > pix_max_val) cal_red = pix_max_val;
else if(cal_red < 0) cal_red = 0;
if(cal_green > pix_max_val) cal_green = pix_max_val;
else if(cal_green < 0) cal_green = 0;
if(cal_blue > pix_max_val) cal_blue = pix_max_val;
else if(cal_blue < 0) cal_blue = 0;
// save calibrated color values at output image
img_calib[index] = cal_red;
img_calib[index+1] = cal_green;
img_calib[index+2] = cal_blue;
index += 3;
}
}
}
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