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/**
* @file alg_interpolate_mono_scalar.h
* @brief Monochrome pixel interpolation (scalar code)
* @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 a monochrome pixel interpolator and is independent of the pixel-bit-depth. Including this code at the
* C-Source file will define the pixel-bit-depth (see camera_calib.c).
*/
// static void interpolate_mono8_scalar(uint8_t *img_out, const int x, const int y, const int height, const int width,
// const uint8_t *img_in, const int coord_x, const int coord_y, const int scale_fact)
// static void interpolate_mono16_scalar(uint16_t *img_out, const int x, const int y, const int height, const int width,
// const uint16_t *img_in, const int coord_x, const int coord_y, const int scale_fact)
{
int x_start, y_start, x_end, y_end, index_start, index_end;
int wheight_x, wheight_y, a11, a12, a21, a22;
int mono;
int index;
const int max_val = (1<<scale_fact);
// calculate pixel index of destination image (calibrated image)
index = ((y*width)+x);
if((coord_x>>scale_fact) > width || (coord_y>>scale_fact) > height || coord_x < 0 || coord_y < 0) {
// out of range --> return black value
img_out[index] = 0;
return;
}
mono = 0;
x_start = coord_x>>scale_fact;
y_start = coord_y>>scale_fact;
x_end = x_start + 1;
y_end = y_start + 1;
index_start = (y_start*width + x_start);
index_end = (y_end*width + x_end);
// calculate wheights
wheight_x = coord_x % max_val;
wheight_y = coord_y % max_val;
a11 = (max_val - wheight_x)*(max_val - wheight_y);
a12 = wheight_x*(max_val - wheight_y);
a21 = (max_val - wheight_x)*wheight_y;
a22 = wheight_x*wheight_y;
/*
* handle border region separately
*/
if(x_end < width || y_end < height) {
// pixels are not lying on border region
mono = img_in[index_start]*a11 +
img_in[index_start+1]*a12 +
img_in[index_end-1]*a21 +
img_in[index_end]*a22;
}
img_out[index] = mono >> (2*scale_fact);
}
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