comparison Meerwald/cmp_corvi_sig.c @ 0:be303a3f5ea8

import
author Peter Meerwald <pmeerw@cosy.sbg.ac.at>
date Sun, 12 Aug 2007 13:14:34 +0200
parents
children f83ef905a63d
comparison
equal deleted inserted replaced
-1:000000000000 0:be303a3f5ea8
1 #include "wm.h"
2
3 char *progname;
4
5 void usage(void) {
6 fprintf(stderr, "usage: %s [-h] [-C] [-o file] [-v n] -s file file\n\n", progname);
7 fprintf(stderr, "\t-C\t\toutput correlation only\n");
8 fprintf(stderr, "\t-h\t\tprint usage\n");
9 fprintf(stderr, "\t-o file\t\toutput file\n");
10 fprintf(stderr, "\t-v n\t\tverbosity level\n");
11 fprintf(stderr, "\t-s file\t\toriginal signature file\n");
12 exit(0);
13 }
14
15 int main(int argc, char *argv[]) {
16
17 FILE *in = stdin;
18 FILE *out = stdout;
19 FILE *sig = NULL;
20
21 char signature_name[MAXPATHLEN];
22 char output_name[MAXPATHLEN] = "(stdout)";
23 char input_name[MAXPATHLEN] = "(stdin)";
24
25 int c;
26 int sig_n, in_n;
27 double s1, s2, s3;
28 char line[32];
29 int matches;
30
31 int verbose = 0;
32 int correlation_only = 0;
33
34 progname = argv[0];
35
36 while ((c = getopt(argc, argv, "h?o:s:v:C")) != EOF) {
37 switch (c) {
38 case 'h':
39 case '?':
40 usage();
41 break;
42 case 'o':
43 if ((out = fopen(optarg, "w")) == NULL) {
44 fprintf(stderr, "%s: unable to open output file %s\n", progname, optarg);
45 exit(1);
46 }
47 strcpy(output_name, optarg);
48 break;
49 case 's':
50 if ((sig = fopen(optarg, "r")) == NULL) {
51 fprintf(stderr, "%s: unable to open signature file %s\n", progname, optarg);
52 exit(1);
53 }
54 strcpy(signature_name, optarg);
55 break;
56 case 'v':
57 verbose = atoi(optarg);
58 if (verbose < 0) {
59 fprintf(stderr, "%s: verbosity level %d out of range\n", progname, verbose);
60 exit(1);
61 }
62 break;
63 case 'C':
64 correlation_only = 1;
65 break;
66 }
67 }
68
69 argc -= optind;
70 argv += optind;
71
72 if (argc > 1) {
73 usage();
74 exit(1);
75 }
76
77 if (argc == 1 && *argv[0] != '-')
78 if ((in = fopen(argv[0], "r")) == NULL) {
79 fprintf(stderr, "%s: unable to open input file %s\n", progname, argv[0]);
80 exit(1);
81 }
82 else
83 strcpy(input_name, argv[0]);
84
85 if (!sig) {
86 fprintf(stderr, "%s: original signature file not specified, use -s file option\n", progname);
87 exit(1);
88 }
89
90 fgets(line, sizeof(line), sig);
91 if (strspn(line, "CVSG") < 4) {
92 fprintf(stderr, "%s: original signature file %s invalid\n", progname, signature_name);
93 exit(1);
94 }
95
96 fgets(line, sizeof(line), in);
97 if (strspn(line, "CVWM") < 4) {
98 fprintf(stderr, "%s: signature file %s invalid\n", progname, input_name);
99 exit(1);
100 }
101
102 fscanf(sig, "%d\n", &sig_n);
103 fscanf(in, "%d\n", &in_n);
104 if (sig_n != in_n) {
105 fprintf(stderr, "%s: watermark length mismatch (original %d, input %d)\n", progname, sig_n, in_n);
106 exit(1);
107 }
108 if (sig_n <= 0 || sig_n > 1000) {
109 fprintf(stderr, "%s: invalid original watermark length %d\n", progname, sig_n);
110 exit(1);
111 }
112 if (in_n <= 0 || in_n > 1000) {
113 fprintf(stderr, "%s: invalid watermark length %d\n", progname, in_n);
114 exit(1);
115 }
116
117 fscanf(sig, "%*lf\n");
118 fscanf(sig, "%*d\n");
119 fscanf(sig, "%*d\n");
120 fscanf(sig, "%*[^\n\r]\n");
121
122 /*
123 * normalized correlation
124 * Craver, S., "Can Invisible Watermarks Resolve Rightful Ownership?", IBM Research Report, 1996, p. 5
125 */
126
127 s1 = s2 = s3 = 0.0;
128 matches = 0;
129 while (in_n > 0) {
130 double sig_x, in_x;
131
132 fscanf(sig, "%lf\n", &sig_x);
133 fscanf(in, "%lf\n", &in_x);
134
135 matches += SIGN(sig_x * in_x);
136
137 if (verbose >= 1) {
138 fprintf(stderr, "orig %f input %f\n", sig_x, in_x);
139 }
140
141 s1 += sig_x * in_x;
142 s2 += in_x * in_x;
143 s3 += sig_x * sig_x;
144
145 in_n--;
146 }
147
148 if (!correlation_only) {
149 fprintf(out, "%s: correlation %f, hamming distance %f\n", progname, s1 / sqrt(s2 * s3), (double) matches / sig_n);
150 }
151 else
152 fprintf(out, "%f\n", (double) matches / sig_n);
153
154 fclose(sig);
155 fclose(out);
156 fclose(in);
157
158 exit(0);
159 }

Repositories maintained by Peter Meerwald, pmeerw@pmeerw.net.