--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Meerwald-dir/wm_zhu_e.c	Fri Dec 20 13:08:59 2024 +0100
@@ -0,0 +1,261 @@
+#include "wm.h"
+#include "dwt.h"
+#include "netpbm/pgm.h"
+#include "sort.h"
+
+char *progname;
+
+void usage(void) {
+  fprintf(stderr, "usage: %s [-a n] [-e n] [-f n] [-F n] [-h] [-l n] [-o file] [-v n] -s file file\n\n", progname);
+  fprintf(stderr, "\t-a n\t\talpha factor/embedding strength\n");
+  fprintf(stderr, "\t-e n\t\twavelet filtering method\n");
+  fprintf(stderr, "\t-f n\t\tfilter number\n");
+  fprintf(stderr, "\t-F file\t\tfilter definition file\n");
+  fprintf(stderr, "\t-h\t\tprint usage\n");
+  fprintf(stderr, "\t-l n\t\tdecomposition level\n");
+  fprintf(stderr, "\t-o file\t\toutput (watermarked) file\n");
+  fprintf(stderr, "\t-s file\t\tsignature to embed in input image\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 output_name[MAXPATHLEN] = "(stdout)";
+  char input_name[MAXPATHLEN] = "(stdin)";
+  char signature_name[MAXPATHLEN];
+
+  int i, c, w;
+  int row;
+
+  int n;
+
+  double alpha = 0.0;
+  int level = 0;
+
+  int filter = 0;
+  int method = -1;
+  int levels;
+  char filter_name[MAXPATHLEN] = "";
+
+  int verbose = 0;
+
+  gray **image;
+  Image_tree p, dwts;
+
+  gray maxval;
+  int rows, cols, format;
+
+  double *watermark;
+
+  progname = argv[0];
+
+  pgm_init(&argc, argv); wm_init();
+
+  while ((c = getopt(argc, argv, "a:e:f:F:h?o:l:s:v:")) != EOF) {
+    switch (c) {
+      case 'a':
+        alpha = atof(optarg);
+        if (alpha <= 0.0) {
+          fprintf(stderr, "%s: alpha factor %f out of range\n", progname, alpha);
+          exit(1);
+        }
+        break;
+      case 'l':
+        level = atoi(optarg);
+        if (level <= 0) {
+          fprintf(stderr, "%s: decomposition level %d out of range\n", progname, level);
+          exit(1);
+        }
+        break;
+      case 'e':
+        method = atoi(optarg);
+        if (method < 0) {
+          fprintf(stderr, "%s: wavelet filtering method %d out of range\n", progname, method);
+          exit(1);
+        }
+        break;
+      case 'f':
+        filter = atoi(optarg);
+        if (filter <= 0) {
+          fprintf(stderr, "%s: filter number %d out of range\n", progname, filter);
+          exit(1);
+        }
+        break;
+      case 'F':
+        strcpy(filter_name, optarg);
+        break;
+      case 'h':
+      case '?':
+        usage();
+        break;
+      case 'o':
+        if ((out = fopen(optarg, "wb")) == 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], "rb")) == NULL) {
+      fprintf(stderr, "%s: unable to open input file %s\n", progname, argv[0]);
+      exit(1);
+    }
+    else
+      strcpy(input_name, argv[0]);
+  }
+  
+  if (sig) {
+    char line[32];
+    fgets(line, sizeof(line), sig);
+    if (strspn(line, "ZHSG") >= 4) {
+      fscanf(sig, "%d\n", &n);
+      if (alpha == 0.0)
+        fscanf(sig, "%lf\n", &alpha);
+      else
+        fscanf(sig, "%*f\n");
+      if (level == 0)
+        fscanf(sig, "%d\n", &level);
+      else
+        fscanf(sig, "%*d\n");
+      if (method < 0)
+        fscanf(sig, "%d\n", &method);
+      else
+        fscanf(sig, "%*d\n");
+      if (filter == 0)
+        fscanf(sig, "%d\n", &filter);
+      else
+        fscanf(sig, "%*d\n");
+      if (!strcmp(filter_name, ""))
+        fscanf(sig, "%[^\n\r]\n", filter_name);
+      else
+        fscanf(sig, "%*[^\n\r]\n");
+    }
+    else {
+      fprintf(stderr, "%s: invalid signature file %s\n", progname, signature_name);
+      exit(1);
+    }
+  }
+  else {
+    fprintf(stderr, "%s: signature file not specified, use -s file option\n", progname);
+    exit(1);
+  }
+
+  watermark = malloc(n * sizeof(double));
+  for (i = 0; i < n; i++) 
+    fscanf(sig, "%lf\n", &watermark[i]);
+  fclose(sig);
+
+  pgm_readpgminit(in, &cols, &rows, &maxval, &format);
+  image = pgm_allocarray(cols, rows);
+  for (row = 0; row < rows; row++)
+    pgm_readpgmrow(in, image[row], cols, maxval, format);
+  fclose(in);
+
+  // complete decomposition
+  levels = find_deepest_level(cols, rows) - 1;
+  if (level > levels) {
+    fprintf(stderr, "%s: decomposition level %d not possible (max. %d), image size is %d x %d\n", progname, level, levels, cols, rows);
+    exit(1);
+  }
+
+  // wavelet transform
+  init_dwt(cols, rows, filter_name, filter, level, method);
+#ifdef POLLEN_STUFF
+#include "pollen_stuff.c"
+#endif
+#ifdef PARAM_STUFF
+#include "param_stuff.c"
+#endif
+
+  dwts = fdwt(image);
+
+  p = dwts;
+  while (p->coarse) {
+    double *collected_coeffs, *largest;
+    int subband_size = p->horizontal->image->size;
+    int maxselect = MIN(3 * subband_size, n + 1);
+    double threshold;
+
+    // allocate memory for coefficient vector
+    collected_coeffs = malloc(3 * subband_size * sizeof(double));
+    if (!collected_coeffs) {
+      fprintf(stderr, "%s: malloc() failed\n", progname);
+      exit(1);
+    }
+
+    // collect coefficients from all subbands of one level into one vector
+    for (i = 0; i < subband_size; i++) {
+      collected_coeffs[3 * i + 0] = p->horizontal->image->data[i];
+      collected_coeffs[3 * i + 1] = p->vertical->image->data[i];
+      collected_coeffs[3 * i + 2] = p->diagonal->image->data[i];
+    }
+
+    // allocate memory for largest coefficients
+    largest = malloc(maxselect * sizeof(double));
+    if (!largest) {
+      fprintf(stderr, "%s: malloc() failed\n", progname);
+      exit(1);
+    }
+
+    // select largest coefficients (involves sorting)
+    select_largest_coeffs(collected_coeffs, 3 * subband_size, maxselect, largest);
+    // threshold is the smallest of the largest coefficients 
+    threshold = largest[0];
+    free(largest);
+    free(collected_coeffs);
+
+    w = 0;
+    for (i = 0; i < subband_size && w < n; i++) {
+      if (p->horizontal->image->data[i] > threshold)
+        p->horizontal->image->data[i] *= (1.0 + alpha * watermark[w++]);
+      if (p->vertical->image->data[i] > threshold)
+        p->vertical->image->data[i] *= (1.0 + alpha * watermark[w++]);
+      if (p->diagonal->image->data[i] > threshold)
+        p->diagonal->image->data[i] *= (1.0 + alpha * watermark[w++]);
+    }
+
+    p = p->coarse;
+  }
+
+  free(watermark);
+  idwt(dwts, image);
+
+  pgm_writepgminit(out, cols, rows, maxval, 0);
+  for (row = 0; row < rows; row++)
+    pgm_writepgmrow(out, image[row], cols, maxval, 0);
+  fclose(out);
+
+  pgm_freearray(image, rows);
+
+  exit(0);
+}