Mercurial > hg > wm
comparison Meerwald-dir/cmp_corvi_sig.c @ 24:9f20bce6184e v0.7
move directories, support netpbm 11
| author | Peter Meerwald-Stadler <pmeerw@pmeerw.net> |
|---|---|
| date | Fri, 20 Dec 2024 13:08:59 +0100 |
| parents | Meerwald/cmp_corvi_sig.c@4987db85cfae |
| children |
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| 23:71dd4b96221b | 24:9f20bce6184e |
|---|---|
| 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 | |
| 86 if (!sig) { | |
| 87 fprintf(stderr, "%s: original signature file not specified, use -s file option\n", progname); | |
| 88 exit(1); | |
| 89 } | |
| 90 | |
| 91 fgets(line, sizeof(line), sig); | |
| 92 if (strspn(line, "CVSG") < 4) { | |
| 93 fprintf(stderr, "%s: original signature file %s invalid\n", progname, signature_name); | |
| 94 exit(1); | |
| 95 } | |
| 96 | |
| 97 fgets(line, sizeof(line), in); | |
| 98 if (strspn(line, "CVWM") < 4) { | |
| 99 fprintf(stderr, "%s: signature file %s invalid\n", progname, input_name); | |
| 100 exit(1); | |
| 101 } | |
| 102 | |
| 103 fscanf(sig, "%d\n", &sig_n); | |
| 104 fscanf(in, "%d\n", &in_n); | |
| 105 if (sig_n != in_n) { | |
| 106 fprintf(stderr, "%s: watermark length mismatch (original %d, input %d)\n", progname, sig_n, in_n); | |
| 107 exit(1); | |
| 108 } | |
| 109 if (sig_n <= 0 || sig_n > 1000) { | |
| 110 fprintf(stderr, "%s: invalid original watermark length %d\n", progname, sig_n); | |
| 111 exit(1); | |
| 112 } | |
| 113 if (in_n <= 0 || in_n > 1000) { | |
| 114 fprintf(stderr, "%s: invalid watermark length %d\n", progname, in_n); | |
| 115 exit(1); | |
| 116 } | |
| 117 | |
| 118 fscanf(sig, "%*f\n"); | |
| 119 fscanf(sig, "%*d\n"); | |
| 120 fscanf(sig, "%*d\n"); | |
| 121 fscanf(sig, "%*[^\n\r]\n"); | |
| 122 | |
| 123 /* | |
| 124 * normalized correlation | |
| 125 * Craver, S., "Can Invisible Watermarks Resolve Rightful Ownership?", IBM Research Report, 1996, p. 5 | |
| 126 */ | |
| 127 | |
| 128 s1 = s2 = s3 = 0.0; | |
| 129 matches = 0; | |
| 130 while (in_n > 0) { | |
| 131 double sig_x, in_x; | |
| 132 | |
| 133 fscanf(sig, "%lf\n", &sig_x); | |
| 134 fscanf(in, "%lf\n", &in_x); | |
| 135 | |
| 136 matches += SIGN(sig_x * in_x); | |
| 137 | |
| 138 if (verbose >= 1) { | |
| 139 fprintf(stderr, "orig %f input %f\n", sig_x, in_x); | |
| 140 } | |
| 141 | |
| 142 s1 += sig_x * in_x; | |
| 143 s2 += in_x * in_x; | |
| 144 s3 += sig_x * sig_x; | |
| 145 | |
| 146 in_n--; | |
| 147 } | |
| 148 | |
| 149 if (!correlation_only) { | |
| 150 fprintf(out, "%s: correlation %f, hamming distance %f\n", progname, s1 / sqrt(s2 * s3), (double) matches / sig_n); | |
| 151 } | |
| 152 else | |
| 153 fprintf(out, "%f\n", (double) matches / sig_n); | |
| 154 | |
| 155 fclose(sig); | |
| 156 fclose(out); | |
| 157 fclose(in); | |
| 158 | |
| 159 exit(0); | |
| 160 } |