--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Meerwald-dir/wm_frid2_e.c	Fri Dec 20 13:08:59 2024 +0100
@@ -0,0 +1,218 @@
+#include "wm.h"
+#include "dct.h"
+#include "netpbm/pgm.h"
+#include "signature.h"
+#include "frid2_common.h"
+
+char *progname;
+
+void usage(void) {
+  fprintf(stderr, "usage: %s [-a n] [-g n] [-n n] [-h] [-o file] [-v n] -s file file\n\n", progname);
+  fprintf(stderr, "\t-a n\t\talpha factor low freq. embedding strength\n");
+  fprintf(stderr, "\t-g n\t\tgamma factor med freq. embedding strength\n");
+  fprintf(stderr, "\t-h\t\tprint usage\n");
+  fprintf(stderr, "\t-n n\t\tnormalisation factor (default 1024.0)\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 c;
+  int row, col;
+  double normalization = 1024.0;
+  int seed, format;
+
+  double alpha = 0.0;
+  double gamma = 0.0;
+
+  gray **image;
+  double **coeffs;
+
+  double mean, derivation;
+  double mult_factor;
+
+  int rows, cols;
+  int verbose = 0;
+  gray maxval;
+
+  progname = argv[0];
+
+  pgm_init(&argc, argv); wm_init();
+
+  while ((c = getopt(argc, argv, "a:g:n:h?o: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 'g':
+        gamma = atof(optarg);
+        if (gamma <= 0.0) {
+          fprintf(stderr, "%s: gamma factor %f out of range\n", progname, alpha);
+          exit(1);
+        }
+        break;
+      case 'n':
+        normalization = atof(optarg);
+        if (normalization < 0) {
+          fprintf(stderr, "%s: normalisation factor %f out of range\n", progname, normalization);
+          exit(1);
+        }
+        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, "FR2SG") >= 5) {
+      fscanf(sig, "%d\n", &nbit_signature);
+      if (alpha == 0.0)
+        fscanf(sig, "%lf\n", &alpha);
+      else
+        fscanf(sig, "%*f\n");
+      if (gamma == 0.0)
+        fscanf(sig, "%lf\n", &gamma);
+      else
+        fscanf(sig, "%*f\n");
+      
+      fscanf(sig, "%d\n", &seed);
+      n_signature = NBITSTOBYTES(nbit_signature);
+      fread(signature, sizeof(char), n_signature, sig);
+      fscanf(sig, "\n");
+      srandom(seed);
+    }
+    else {
+      fprintf(stderr, "%s: invalid signature file %s\n", progname, signature_name);
+      exit(1);
+    }
+    fclose(sig);
+  }
+  else {
+    fprintf(stderr, "%s: signature file not specified, use -s file option\n", progname);
+    exit(1);
+  }
+
+  pgm_readpgminit(in, &cols, &rows, &maxval, &format);
+
+  if (rows == cols)
+    init_dct_NxN(cols, rows);
+  else
+    init_dct_NxM(cols, rows);
+
+  image = pgm_allocarray(cols, rows);
+  for (row = 0; row < rows; row++)
+    pgm_readpgmrow(in, image[row], cols, maxval, format);
+  fclose(in);
+
+  // calculate mean value
+  mean = 0.0;
+  for (row = 0; row < rows; row++)
+    for (col = 0; col < cols; col++)
+      mean += image[row][col];
+
+  mean /= cols * rows;
+
+  // calculate derivation
+  derivation = 0.0;
+  for (row = 0; row < rows; row++)
+    for (col = 0; col < cols; col++)
+      derivation += sqr(image[row][col] - mean);
+    
+  derivation = sqrt(derivation / (cols * rows - 1));
+  mult_factor = normalization / (sqrt(cols * rows) * derivation); 
+
+  if (verbose > 5)
+    fprintf(stderr, "%s: mean %f, derivation %f, mult_factor %f\n", progname, mean, derivation, mult_factor);
+
+  // normalize image
+  coeffs = alloc_coeffs(cols, rows);
+  for (row = 0; row < rows; row++)
+    for (col = 0; col < cols; col++)
+      coeffs[row][col] = (image[row][col] - mean) * mult_factor;
+    
+  if (cols == rows)
+    fdct_inplace_NxN(coeffs);
+//  else
+//    fdct_NxM(image, dcts);    
+
+  embed_low_freq(coeffs, cols, rows, alpha, verbose);
+  embed_med_freq(coeffs, cols, rows, gamma, seed, verbose);
+    
+  if (cols == rows)
+    idct_inplace_NxN(coeffs);
+//  else
+//    idct_NxM(dcts, image);
+
+  for (row = 0; row < rows; row++)
+    for (col = 0; col < cols; col++)
+      image[row][col] = PIXELRANGE(coeffs[row][col] / mult_factor + mean + 0.5);
+  
+  free_coeffs(coeffs);
+
+  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);
+}