1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
|
/**
* @file alg_interpolate_rgb_scalar.h
* @brief RGB 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 an RGB 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_rgb8_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_rgb16_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 red, green, blue;
int index;
const int max_val = (1<<scale_fact);
// calculate pixel index of destination image (calibrated image)
index = ((y*width)+x)*3;
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;
img_out[index+1] = 0;
img_out[index+2] = 0;
return;
}
red = 0;
green = 0;
blue = 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)*3;
index_end = (y_end*width + x_end)*3;
// 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
red = img_in[index_start]*a11 +
img_in[index_start+3]*a12 +
img_in[index_end-3]*a21 +
img_in[index_end]*a22;
green = img_in[index_start+1]*a11 +
img_in[index_start+1+3]*a12 +
img_in[index_end+1-3]*a21 +
img_in[index_end+1]*a22;
blue = img_in[index_start+2]*a11 +
img_in[index_start+2+3]*a12 +
img_in[index_end+2-3]*a21 +
img_in[index_end+2]*a22;
}
img_out[index] = red >> (2*scale_fact);
img_out[index+1] = green >> (2*scale_fact);
img_out[index+2] = blue >> (2*scale_fact);
}
|
