--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Meerwald-dir/cmp_xie2_sig.c	Fri Dec 20 13:08:59 2024 +0100
@@ -0,0 +1,151 @@
+#include "wm.h"
+#include "signature.h"
+
+char *progname;
+
+void usage(void) {
+  fprintf(stderr, "usage: %s [-h] [-C] [-o file] [-v n] -s file file\n\n", progname);
+  fprintf(stderr, "\t-C\t\toutput correlation only\n");
+  fprintf(stderr, "\t-h\t\tprint usage\n");
+  fprintf(stderr, "\t-o file\t\toutput file\n");
+  fprintf(stderr, "\t-s file\t\toriginal signature file\n");
+  fprintf(stderr, "\t-v n\t\tverbosity level\n");
+  exit(0);
+}
+
+int main(int argc, char *argv[]) {
+
+  FILE *in = stdin;
+  FILE *out = stdout;
+  FILE *sig = NULL;
+
+  char signature_name[MAXPATHLEN];
+  char output_name[MAXPATHLEN] = "(stdout)";
+  char input_name[MAXPATHLEN] = "(stdin)";
+
+  int correlation_only = 0;
+
+  int c, i;
+  int corr = 0, match = 0;
+  int verbose = 0;
+  int filter = 0;
+  int method = 0;
+  int level = 0;
+  int quant = 0;
+  double alpha = 0.0;
+  char filter_name[MAXPATHLEN] = "";
+
+  int seed;
+  char line[32];
+
+  progname = argv[0];
+
+  while ((c = getopt(argc, argv, "h?Co:s:v:")) != EOF) {
+    switch (c) {
+      case 'h':
+      case '?':
+        usage();
+        break; 
+      case 'C':
+        correlation_only = 1;
+        break;
+      case 'o':
+        if ((out = fopen(optarg, "w")) == NULL) {
+          fprintf(stderr, "%s: unable to open output file %s\n", progname, optarg);
+          exit(1);
+        }
+        strcpy(output_name, optarg);
+        break;
+      case 's':
+        if ((sig = fopen(optarg, "r")) == NULL) {
+          fprintf(stderr, "%s: unable to open signature file %s\n", progname, optarg);
+          exit(1);
+        }
+        strcpy(signature_name, optarg);
+        break;
+     case 'v':
+        verbose = atoi(optarg);
+        if (verbose < 0) {
+          fprintf(stderr, "%s: verbosity level %d out of range\n", progname, verbose);
+          exit(1);
+        }
+        break;
+    }
+  }
+
+  argc -= optind;
+  argv += optind;
+
+  if (argc > 1) {
+    usage();
+    exit(1);
+  }
+
+  if (argc == 1 && *argv[0] != '-') {
+    if ((in = fopen(argv[0], "r")) == NULL) {
+      fprintf(stderr, "%s: unable to open input file %s\n", progname, argv[0]);
+      exit(1);
+    }
+    else
+      strcpy(input_name, argv[0]);
+  }
+  
+  if (sig) {
+    fgets(line, sizeof(line), sig);
+    if (strspn(line, "XE2SG") >= 5) {
+      fscanf(sig, "%d\n", &nbit_signature1);
+      fscanf(sig, "%lf\n", &alpha);
+      fscanf(sig, "%d\n", &method);
+      fscanf(sig, "%d\n", &filter);
+      fscanf(sig, "%[^\n\r]\n", filter_name);
+      fscanf(sig, "%d\n", &quant);
+      fscanf(sig, "%d\n", &level);
+      fscanf(sig, "%d\n", &seed);
+      srandom(seed);
+      n_signature1 = NBITSTOBYTES(nbit_signature1);
+      fread(signature1, sizeof(char), n_signature1, sig);
+      fscanf(sig, "\n");
+    }
+    else {
+      fprintf(stderr, "%s: invalid signature file %s\n", progname, signature_name);
+      exit(1);
+    }
+    fclose(sig);
+  }
+  else {
+    fprintf(stderr, "%s: original signature file not specified, use -s file option\n", progname);
+    exit(1);
+  }
+
+  fgets(line, sizeof(line), in);
+  if (strspn(line, "XE2WM") >= 5) {
+    fscanf(in, "%d\n", &nbit_signature2);
+    n_signature2 = NBITSTOBYTES(nbit_signature2);
+    fread(signature2, sizeof(char), n_signature2, in);
+    fscanf(in, "\n");    
+  }
+  else {
+    fprintf(stderr, "%s: invalid watermark file %s\n", progname, input_name);
+    exit(1);
+  }
+
+  if (verbose > 0) {
+    fprintf(stderr, "signature length: %d\n", nbit_signature1);
+    fprintf(stderr, "watermark length: %d\n", nbit_signature2);
+  }
+
+  for (i = 0; i < nbit_signature2; i++)
+    if (get_signature1_bit(i % nbit_signature1) == get_signature2_bit(i))
+      corr++, match++;
+    else
+      corr--;
+
+  if (correlation_only)
+    fprintf(out, "%lf\n", (double) corr / nbit_signature2);
+  else {
+    fprintf(out, "bit matches: %d/%d\n", match, nbit_signature2);
+    fprintf(out, "correlation: %lf\n", (double) corr / nbit_signature2);
+  }
+
+  exit(0);
+}