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
|
#include <stdio.h>
#include <math.h>
#include <ppm.h>
int main (int argc, char **argv) {
FILE *strip = NULL;
FILE *window = NULL;
int stripRows, stripCols, stripFormat;
int windowRows, windowCols, windowFormat;
pixval stripMaxval, windowMaxval;
pixel **stripArray, **windowArray;
register int marginH, marginV;
register int deltaH, deltaV;
int bestDeltaH, bestDeltaV, bestErr, interval;
register int row, col, err;
register double errSumSquare;
#define DIFF(p,q) ((p)>(q)?((p)-(q)):((q)-(p)))
pixel stripPixel, windowPixel;
if (argc < 3) {
fprintf(stderr, "Usage: match stripfile.ppm windowfile.ppm [interval]\n");
exit(1);
}
interval = 0;
if (argc > 3) {
interval = atoi(argv[3]);
}
if (interval < 1) {
interval = 1;
}
strip = fopen(argv[1], "r");
if (!strip) {
perror("Can't open strip file");
exit(1);
}
window = fopen(argv[2], "r");
if (!window) {
perror("Can't open window file");
exit(1);
}
stripArray = ppm_readppm(strip, &stripCols, &stripRows, &stripMaxval);
if (stripMaxval != 255) {
fprintf(stderr, "Strip file is not a PPM, maxval 255\n");
exit(1);
}
windowArray = ppm_readppm(window, &windowCols, &windowRows, &windowMaxval);
if (windowMaxval != 255) {
fprintf(stderr, "Window file is not a PPM, maxval 255\n");
exit(1);
}
marginH = (windowCols - stripCols) / 2;
marginV = (windowRows - stripRows) / 2;
bestErr = 0x7FFFFFFF;
for (deltaH = -marginH ; deltaH <= marginH; deltaH += interval) {
for (deltaV = -marginV ; deltaV <= marginV; deltaV += interval) {
/*
* TBD - review the sign of deltaV to make sure it has the same sense
* as exists elsewhere in the tool chain
*/
errSumSquare = 0.0;
for (row = 0 ; row < stripRows; row++) {
for (col = 0 ; col < stripCols; col ++) {
stripPixel = stripArray[row][col];
windowPixel = windowArray[row+marginV+deltaV][col+marginH+deltaH];
err = ((299 * DIFF(stripPixel.r,windowPixel.r)) +
(587 * DIFF(stripPixel.g,windowPixel.g)) +
(114 * DIFF(stripPixel.b,windowPixel.b))) / 1000;
errSumSquare += err * err;
}
}
errSumSquare /= stripRows * stripCols / 10;
err = (int) sqrt(errSumSquare);
if (err < bestErr) {
bestErr = err;
bestDeltaH = deltaH;
bestDeltaV = deltaV;
fprintf(stderr, "Offset %d %d error %d\n", deltaH, deltaV, err);
}
}
}
fclose(strip);
fclose(window);
printf("%d %d %d\n", bestDeltaH, bestDeltaV, bestErr);
}
|
