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
|
#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#include <math.h>
#include <string.h>
#include <unistd.h>
#include <ppm.h>
double linear(double x) {
return(x);
}
double sigmoid(double x) {
double gain = 0.5e4;
double threshold = 0.0005;
double default_val = 0.05;
double ret_val;
ret_val = default_val + (x - default_val)/(1 + exp(-gain*(x - threshold)));
return(ret_val);
}
double threshold(double x) {
double t = 0.0005;
double ret_val;
if (x > t)
ret_val = x;
else
ret_val = 1;
return(ret_val);
}
int main(int argc, char *argv[]) {
FILE *source_file, *normalized_image_file;
PPM *source_image, *normalized_image;
double *dbl_normalized_image;
enum file_types ppm_type;
enum ppm_error the_error;
int window_size;
switch(argc) {
case 2:
window_size = atoi(argv[1]);
break;
default:
fprintf(stderr, "Usage: ppm_normalize window_size < file1.ppm > file2.ppm\n\n");
exit(1);
break;
}
/* act as a pipe */
source_file = stdin;
normalized_image_file = stdout;
switch(ppm_type = read_magic_no(source_file)) {
case PGM_ASC: case PPM_ASC: case PGM_RAW: case PPM_RAW:
if ((the_error = read_ppm(source_file, &source_image, ppm_type)) != PPM_OK) {
ppm_handle_error(the_error);
exit(1);
}
break;
default:
fprintf(stderr, "Unrecognized file type.\n");
exit(1);
break;
}
dbl_normalized_image = ppm_local_normalize(source_image, window_size, sigmoid);
normalized_image = ppm_double_to_byte(dbl_normalized_image, source_image->width, source_image->height);
if ((the_error = write_ppm(normalized_image_file, normalized_image, normalized_image->type)) != PPM_OK) {
ppm_handle_error(the_error);
exit(1);
}
exit(0);
}
|
