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/*
* libopenraw - demoisaic.cpp
*
* 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 3 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, see
* <http://www.gnu.org/licenses/>.
*
* This code has been adapted from GEGL:
* Copyright 2006 Øyvind Kolås <pippin@gimp.org>
* Copyright 2008 Bradley Broom <bmbroom@gmail.com>
*
* In libopenraw:
* Copyright 2008-2009 Hubert Figuiere <hub@figuiere.net>
* Copyright 2008 Novell Inc.
*/
#include <stdlib.h>
#include <algorithm>
#include <libopenraw/demosaic.h>
/*
extern "C" void or_demosaic(uint16_t*, uint32_t, uint32_t, or_cfa_pattern, uint8_t*)
{
}
*/
/* Returns the median of four floats. We define the median as the average of
* the central two elements.
*/
static inline float
m4 (float a, float b, float c, float d)
{
float t;
/* Sort ab */
if (a > b)
{
t = b;
b = a;
a = t;
}
/* Sort abc */
if (b > c)
{
t = c;
c = b;
if (a > t)
{
b = a;
a = t;
}
else
b = t;
}
/* Return average of central two elements. */
if (d >= c) /* Sorted order would be abcd */
return (b + c) / 2.0;
else if (d >= a) /* Sorted order would be either abdc or adbc */
return (b + d) / 2.0;
else /* Sorted order would be dabc */
return (a + b) / 2.0;
}
/* Defines to make the row/col offsets below obvious. */
#define ROW src_x
#define COL 1
/* We expect src_extent to have a one pixel border around all four sides
* of dst_extent.
*/
void
bimedian_demosaic (uint16_t *src, uint32_t src_x, uint32_t src_y,
or_cfa_pattern pattern, uint8_t *dst)
{
uint32_t x,y;
uint32_t offset, doffset;
float *src_buf;
float *dst_buf;
int npattern = 0;
switch(pattern) {
case OR_CFA_PATTERN_GRBG:
npattern = 0;
break;
case OR_CFA_PATTERN_BGGR:
npattern = 1;
break;
case OR_CFA_PATTERN_GBRG:
npattern = 2;
break;
case OR_CFA_PATTERN_RGGB:
npattern = 3;
break;
default:
break;
}
src_buf = (float*)calloc(src_x * src_y, sizeof(float));
dst_buf = (float*)calloc(src_x * src_y * 3, sizeof(float));
std::copy(src, src + (src_x * src_y), src_buf);
offset = ROW + COL;
doffset = 0;
for(y = 1 ; y < src_y - 1; y++)
{
for (x = 1 ; x < src_x - 1; x++)
{
float red=0.0;
float green=0.0;
float blue=0.0;
if ((y + npattern%2)%2==0) {
if ((x+npattern/2)%2==1) {
/* GRG
* BGB
* GRG
*/
blue =(src_buf[offset-COL]+src_buf[offset+COL])/2.0;
green=src_buf[offset];
red =(src_buf[offset-ROW]+src_buf[offset+ROW])/2.0;
}
else {
/* RGR
* GBG
* RGR
*/
blue =src_buf[offset];
green=m4(src_buf[offset-ROW], src_buf[offset-COL],
src_buf[offset+COL], src_buf[offset+ROW]);
red =m4(src_buf[offset-ROW-COL], src_buf[offset-ROW+COL],
src_buf[offset+ROW-COL], src_buf[offset+ROW+COL]);
}
}
else {
if ((x+npattern/2)%2==1) {
/* BGB
* GRG
* BGB
*/
blue =m4(src_buf[offset-ROW-COL], src_buf[offset-ROW+COL],
src_buf[offset+ROW-COL], src_buf[offset+ROW+COL]);
green=m4(src_buf[offset-ROW], src_buf[offset-COL],
src_buf[offset+COL], src_buf[offset+ROW]);
red =src_buf[offset];
}
else {
/* GBG
* RGR
* GBG
*/
blue =(src_buf[offset-ROW]+src_buf[offset+ROW])/2.0;
green=src_buf[offset];
red =(src_buf[offset-COL]+src_buf[offset+COL])/2.0;
}
}
dst_buf [doffset*3+0] = red / 16.0;
dst_buf [doffset*3+1] = green / 16.0;
dst_buf [doffset*3+2] = blue / 16.0;
offset++;
doffset++;
}
offset+=2;
}
std::copy(dst_buf, dst_buf + (src_x * src_y * 3), dst);
free(src_buf);
free(dst_buf);
}
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0))
indent-tabs-mode:nil
fill-column:80
End:
*/
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