--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Fotopoulos-dir/cast-hart.c	Fri Dec 20 13:08:59 2024 +0100
@@ -0,0 +1,113 @@
+/* Watermarking program - Hartley Transform based	*/
+/* Module	: Casting				*/
+/* Author	: Vassilis Fotopoulos			*/
+/* Date		: 26/7/1999				*/
+/* Revision	: 2.01a					*/
+/* Developed at	: ELLAB                  		*/
+/*                Electronics Laboratory           	*/
+/*                Department of Physics             	*/
+/*                University of Patras - GREECE      	*/
+/*		  Copyleft (c) 1999			*/
+/*------------------------------------------------------*/
+/*	pseudorandom noise generator's code is		*/
+/*	taken from "Numerical Recipes in C"		*/
+/*------------------------------------------------------*/
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <float.h>
+#include <getopt.h>
+#include "common.h"
+#include "netpbm/pgm.h"
+
+int height, width;
+
+void add_watermark(double **in, int N, int coeff_start, int wm_length, int wm_key, double wm_alpha)
+{
+  int row, col, count;
+  long int elem, L, M, seed;
+  double a;
+  count = 0;
+  elem = 0;
+  M = coeff_start;
+  L = wm_length;
+  seed = wm_key;
+  a = wm_alpha;
+  for (row = 0; row < N; row++)
+    for (col = 0; col < N; col++) {
+      elem++;
+      if (elem > M && count < L) {
+        in[row][col] += a * fabs(in[row][col]) * gasdev(&seed);
+        count++;
+      }
+    }
+
+}
+
+//--------------------------------------------------------
+int main(int argc, char* argv[])
+{
+  FILE *in, *out;
+  int **image;
+  double **image_i;
+  double **image_d;
+  int c;
+  int N;
+  int coeff_start = 5000, wm_length = 10000, wm_key = 123;
+  double wm_alpha = 0.2;
+
+  pgm_init(&argc, argv); wm_init();
+
+  while ((c = getopt(argc, argv, "a:s:l:k:")) != EOF) {
+    switch (c) {
+        case 'a':
+        wm_alpha = atof(optarg);
+        break;
+        case 's':
+        coeff_start = atoi(optarg);
+        break;
+        case 'l':
+        wm_length = atoi(optarg);
+        break;
+        case 'k':
+        wm_key = atoi(optarg);
+        break;
+    }
+  }
+  argc -= optind;
+  argv += optind;
+
+  in = stdin;
+  out = stdout;
+
+  open_image(in, &width, &height);
+  image = imatrix(height, width);
+  load_image(image, in, width, height);
+
+  if (height == width)
+    N = height;
+  else {
+    fprintf(stderr, "Cannot Proccess non-square images!\n");
+    exit( -11);
+  }
+
+  image_i = dmatrix(height, width);
+  image_d = dmatrix(height, width);
+  if (image_d == NULL) {
+    fprintf(stderr, "Unable to allocate the double array\n");
+    exit(1);
+  }
+  matrix_i2d(image, image_i, N);
+  hartley(image_i, image_d, N);
+  add_watermark(image_d, N, coeff_start, wm_length, wm_key, wm_alpha);
+  hartley(image_d, image_i, N);
+  matrix_d2i(image_i, image, N);
+  save_image(image, out, width, height);
+
+  freematrix_d(image_i, height);
+  freematrix_d(image_d, height);
+  fclose(in);
+  fclose(out);
+  exit(EXIT_SUCCESS);
+}