--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Meerwald-dir/wm_bruyn_e.c	Fri Dec 20 13:08:59 2024 +0100
@@ -0,0 +1,549 @@
+#include "wm.h"
+#include "signature.h"
+#include "coord.h"
+#include "gray.h"
+#include "sort.h"
+#include "bruyn_common.h"
+#include "netpbm/pgm.h"
+
+char *progname;
+
+// prints out program's parameters
+void usage(void) {
+  fprintf(stderr, "usage: %s [-b n] [-h] [-k] [-n n] [-o file] [-pP n] [-q n] [-tT n] [-v n] -s file file\n", progname);
+  fprintf(stderr, "\t-b n\t\tblock size\n");
+  fprintf(stderr, "\t-h\t\tprint usage\n");
+  fprintf(stderr, "\t-k\t\tdisable block skipping\n");
+  fprintf(stderr, "\t-n n\t\tnumber of signature bits to embed\n");
+  fprintf(stderr, "\t-o file\t\toutput (watermarked) file\n");
+  fprintf(stderr, "\t-p n\t\tpattern type for zone 1\n");
+  fprintf(stderr, "\t-P n\t\tpattern type for zone 2\n");
+  fprintf(stderr, "\t-q n\t\tsignature strength\n");
+  fprintf(stderr, "\t-s file\t\tsignature to embed in input image\n");
+  fprintf(stderr, "\t-t n\t\tthreshold for noise\n");
+  fprintf(stderr, "\t-T n\t\tthreshold for slope\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;
+
+  gray** image;
+  gray **block;
+  gray **zone;
+  gray **category1, **category2;
+  gray maxval;
+  double *slope;
+  int rows, cols, format;
+  int c;
+  int i, j;
+  int n;
+  int row;
+  int n_block;
+  int skipping = 0;
+
+  char signature_name[MAXPATHLEN];
+  char input_name[MAXPATHLEN] = "(stdin)";
+  char output_name[MAXPATHLEN] = "(stdout)";
+
+  double quality = 0.0;
+  double threshold_noise = 0.0;
+  double threshold_slope = 0.0;
+  int pattern1 = 0;
+  int pattern2 = 0;
+  int blocksize = 0;
+  int seed;
+
+  int verbose = 0;
+
+  struct coords *coords;
+
+  progname = argv[0];
+
+  pgm_init(&argc, argv); wm_init();
+
+  // parse command line and set options
+  while ((c = getopt(argc, argv, "b:h?n:o:p:P:q:s:t:T:v:k")) != EOF) {
+    switch (c) {
+      case 'k':
+        skipping = 1;
+        break;
+      case 'h':
+      case '?':
+        usage();
+        break;
+      case 'n':
+        nbit_signature = atoi(optarg);
+        if (nbit_signature <= 0 || nbit_signature > NBITSIGNATURE) {
+          fprintf(stderr, "%s: invalid signature length %d\n", progname, nbit_signature);
+          exit(1);
+        }
+        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 'p':
+        pattern1 = atoi(optarg);
+        if (pattern1 <= 0 || pattern1 > NPATTERN) {
+          fprintf(stderr, "%s: pattern type out of range\n", progname);
+          exit(1);
+        }
+        break;
+      case 'P':
+        pattern2 = atoi(optarg);
+        if (pattern2 <= 0 || pattern2 > 3) {
+          fprintf(stderr, "%s: pattern type out of range\n", progname);
+          exit(1);
+        }
+        break;
+      case 'q':
+        quality = atof(optarg);
+        if (quality <= 0) {
+          fprintf(stderr, "%s: quality factor %f out of range\n", progname, quality);
+        }
+        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 't':
+        threshold_noise = atof(optarg);
+        if (threshold_noise <= 0) {
+          fprintf(stderr, "%s: noise threshold %f out of range\n", progname, threshold_noise);
+        }
+        break;
+      case 'T':
+        threshold_slope = atof(optarg);
+        if (threshold_slope <= 0) {
+          fprintf(stderr, "%s: slope threshold %f out of range\n", progname, threshold_slope);
+        }
+        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);
+  }
+
+  // open input image file or read from stdin
+  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]);
+  }
+  
+  // read signature file and set options
+  // command line options override signature file options
+  if (sig) {
+    char line[128];
+    fgets(line, sizeof(line), sig);
+    if (strspn(line, "BRSG") >= 4) {
+      if (nbit_signature == 0)
+        fscanf(sig, "%d\n", &nbit_signature);
+      else
+        fscanf(sig, "%*d\n");
+      if (skipping == 0)
+        fscanf(sig, "%d\n", &skipping);
+      else
+        fscanf(sig, "%*d\n");
+      if (pattern1 == 0)
+        fscanf(sig, "%d\n", &pattern1);
+      else
+        fscanf(sig, "%*d\n");
+      if (pattern2 == 0)
+        fscanf(sig, "%d\n", &pattern2);
+      else
+        fscanf(sig, "%*d\n");
+      if (quality == 0.0)
+        fscanf(sig, "%lf\n", &quality);
+      else
+        fscanf(sig, "%*f\n");
+      if (threshold_noise == 0.0)
+        fscanf(sig, "%lf\n", &threshold_noise);
+      else
+        fscanf(sig, "%*f\n");
+      if (threshold_slope == 0.0)
+        fscanf(sig, "%lf\n", &threshold_slope);
+      else
+        fscanf(sig, "%*f\n");
+      if (blocksize == 0)
+        fscanf(sig, "%d\n", &blocksize);
+      else
+        fscanf(sig, "%*d\n");
+      fscanf(sig, "%d\n", &seed);
+      srandom(seed);
+      fread(signature, sizeof(char), NBITSTOBYTES(nbit_signature), sig);
+      fscanf(sig, "\n");
+    }
+    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);
+  }
+
+  if (pattern1 <= 0 || pattern2 <= 0 || pattern1 > NPATTERN || pattern2 > NPATTERN) {
+    fprintf(stderr, "%s: invalid pattern type specified\n", progname);
+    exit(1);
+  }
+
+  // read dimensions of input image file
+  pgm_readpgminit(in, &cols, &rows, &maxval, &format);
+
+  // see if we can embed all signature bits
+  // we want at least half of the blocks untouched
+  if (((rows / blocksize) * (cols / blocksize)) < nbit_signature / 2) {
+    fprintf(stderr, "%s: image not large enough to embed %d bits of signature\n", progname, nbit_signature);
+    exit(1);
+  }
+  n_block = blocksize * blocksize;
+
+  // allocate structure to remember which blocks we already touched,
+  // allow plenty of room to skip over blocks
+  if ((coords = alloc_coords(nbit_signature * 16)) == NULL) {
+    fprintf(stderr, "%s: unable to allocate memory\n", progname);
+    exit(1);
+  }
+
+  // read in input image file
+  image = pgm_allocarray(cols, rows);
+  for (row = 0; row < rows; row++)
+    pgm_readpgmrow(in, image[row], cols, maxval, format);
+
+  fclose(in);
+
+  row = 0;
+
+  // allocate memory for one block
+  block = alloc_grays(blocksize, blocksize);
+
+  // allocate memory for zone classification
+  zone = alloc_grays(blocksize, blocksize);
+
+  // allocate memory for category classification
+  category1 = alloc_grays(blocksize, blocksize);
+  category2 = alloc_grays(blocksize, blocksize);
+
+  // set up category classification array according to
+  // pattern type parameter
+  for (i = 0; i < blocksize; i++)
+    for (j = 0; j < blocksize; j++) {
+      category1[j][i] = lookup_pattern(pattern1, i, j);
+      category2[j][i] = lookup_pattern(pattern2, i, j);
+    }
+
+  // allocate memory for slope calculation
+  slope = malloc(sizeof(double) * n_block);
+
+  // embed all the signature bits, one by one
+  n = 0;
+  while (n < nbit_signature) {
+    int xb;
+    int yb;
+    int blocktype;
+    double smax;
+    int alpha, beta_minus, beta_plus;
+    double mean_1A, mean_1B, mean_2A, mean_2B, mean_1, mean_2;
+    double mean__1A, mean__1B, mean__2A, mean__2B;
+    int n_1A, n_1B, n_2A, n_2B, n_1, n_2;
+    int var_1A, var_1B, var_2A, var_2B;
+    int zone1_ok, zone2_ok;
+
+    // find an unused block randomly, depending on seed
+    do {
+      xb = random() % (cols / blocksize);
+      yb = random() % (rows / blocksize);
+    } while (add_coord(coords, xb, yb) < 0);
+
+    // copy image block
+    copy_grays_to_block(block, image, xb * blocksize, yb * blocksize, blocksize, blocksize);
+
+    if (verbose > 0)
+      fprintf(stderr, "embedding bit #%d (= %d) in block at (%d/%d)\n", n, get_signature_bit(n), xb * blocksize, yb * blocksize);
+    if (verbose > 8) {
+      print_grays(image, xb * blocksize, yb * blocksize, blocksize, blocksize);
+      fprintf(stderr, "\n");
+    }
+
+    // sort luminance values in block to represent increasing function F
+    sort_grays(block[0], n_block);
+
+    if (verbose > 8) {
+      print_grays(block, 0, 0, blocksize, blocksize);
+      fprintf(stderr, "\n");
+    }
+
+    // calculate slopes of F and determine smax, the max. slope of F
+    // the index where smax occures is called alpha
+    alpha = 0;
+    smax = 0.0;
+    for (i = 0; i < n_block - 1; i++) {
+      slope[i] = block[0][i + 1] - block[0][i];
+      if (slope[i] > smax) {
+        smax = slope[i];
+        alpha = i;
+      }
+    }
+    slope[n_block - 1] = 0;
+
+    // block type classification
+    blocktype = BLOCKTYPE_UNKNOWN;
+
+    if (smax < threshold_noise) {
+      // block has noise contrast
+     
+       blocktype = BLOCKTYPE_NOISE;
+      beta_minus = beta_plus = alpha;
+    }
+    else {
+      // block has progressive or hard contrast, let's find out...
+
+      beta_minus = alpha - 1;
+      while (beta_minus >= 0 && smax - slope[beta_minus] <= threshold_slope)
+        beta_minus--;
+
+      beta_plus = alpha + 1;
+      while (beta_plus < n_block && smax - slope[beta_plus] <= threshold_slope)
+        beta_plus++;
+
+      if (beta_minus + 1 == alpha && beta_plus - 1 == alpha)
+        blocktype = BLOCKTYPE_HARD;
+      else 
+        blocktype = BLOCKTYPE_PROGRESSIVE;
+    }
+
+    if (verbose > 1) {
+      fprintf(stderr, "blocktype: %d\n", blocktype); 
+      fprintf(stderr, "Smax = %lf, alpha = %d, beta- = %d, beta+ = %d\n", smax, alpha, beta_minus, beta_plus);
+    }
+
+    // block pixel classification
+    for (i = 0; i < blocksize; i++)
+      for (j = 0; j < blocksize; j++) {
+        gray pixel = image[yb * blocksize + j][xb * blocksize + i];
+        zone[j][i] = ZONE_VOID;
+        switch (blocktype) {
+          case BLOCKTYPE_PROGRESSIVE:
+          case BLOCKTYPE_HARD:
+            if (pixel < block[0][beta_minus])
+              zone[j][i] = ZONE_1;  
+            else if (pixel > block[0][beta_plus])
+              zone[j][i] = ZONE_2;  
+            break;
+          case BLOCKTYPE_NOISE:
+            if (pixel < block[0][n_block / 2])
+              zone[j][i] = ZONE_1;
+            else if (pixel > block[0][n_block / 2])
+              zone[j][i] = ZONE_2;
+            break;
+          default:
+            fprintf(stderr, "%s: invalid block type\n", progname);
+            break;
+        }
+      }
+ 
+    if (verbose > 8) {
+      print_grays(zone, 0, 0, blocksize, blocksize);
+      fprintf(stderr, "\n");
+    }
+
+    // calculate mean values for zone/categories
+    mean_1A = mean_1B = mean_2A = mean_2B = mean_1 = mean_2 = 0.0;
+    mean__1A = mean__1B = mean__2A = mean__2B  = 0.0;
+    n_1A = n_1B = n_2A = n_2B = n_1 = n_2 = 0;
+    for (i = 0; i < blocksize; i++)
+      for (j = 0; j < blocksize; j++) {
+        gray pixel = image[yb * blocksize + j][xb * blocksize + i];
+        int pixel_zone = zone[j][i];
+        int pixel_category = CATEGORY_VOID;
+        if (pixel_zone == ZONE_1)
+          pixel_category = category1[j][i];
+        else if (pixel_zone == ZONE_2)
+          pixel_category = category2[j][i];
+
+        switch (pixel_zone | pixel_category) {
+          case CLASSIFICATION_1A:
+            n_1++;
+            n_1A++;
+            mean_1A += pixel;
+            mean_1 += pixel;
+            break;
+          case CLASSIFICATION_1B:
+            n_1++;
+            n_1B++;
+            mean_1B += pixel;
+            mean_1 += pixel;
+            break;
+          case CLASSIFICATION_2A:
+            n_2++;
+            n_2A++;
+            mean_2A += pixel;
+            mean_2 += pixel;
+            break;
+          case CLASSIFICATION_2B:
+            n_2++;
+            n_2B++;
+            mean_2B += pixel;
+            mean_2 += pixel;
+            break;
+        }
+      }
+
+    if (n_1 && n_1A && n_1B) {
+      mean_1 /= (double) n_1;
+      mean_1A /= (double) n_1A;
+      mean_1B /= (double) n_1B;
+      zone1_ok = 1;
+    }
+    else {
+      mean_1 = mean_1A = mean_1B = 0.0;
+      zone1_ok = 0;
+      if (verbose > 0)
+        fprintf(stderr, "zone 1 unusable\n");
+    }
+    
+    if (n_2 && n_2A && n_2B) {
+      mean_2 /= (double) n_2;
+      mean_2A /= (double) n_2A;
+      mean_2B /= (double) n_2B;
+      zone2_ok = 1;
+    }
+    else {
+      mean_2 = mean_2A = mean_2B = 0.0;
+      zone2_ok = 0;
+      if (verbose > 0)
+        fprintf(stderr, "zone 2 unusable\n");
+    }
+
+    if (!skipping && !zone1_ok && !zone2_ok) {
+      // pathological case - can it ever happen?
+      if (verbose > 0)
+        fprintf(stderr, "block skipped\n");
+      continue;
+    }
+
+    if (verbose > 2) {
+      fprintf(stderr, "m_1 = %lf, m_1A = %lf, m_1B = %lf\n", mean_1, mean_1A, mean_1B);
+      fprintf(stderr, "m_2 = %lf, m_2A = %lf, m_2B = %lf\n", mean_2, mean_2A, mean_2B);
+    }
+
+    // calculate new mean values required by embedding rule
+    if (get_signature_bit(n)) {
+      if (zone1_ok) {
+        mean__1A = (mean_1 * (double) (n_1A + n_1B) + (double) n_1B * quality) / (double) (n_1A + n_1B);
+        mean__1B = mean__1A - quality;
+      }
+      if (zone2_ok) {
+        mean__2A = (mean_2 * (double) (n_2A + n_2B) + (double) n_2B * quality) /  (double) (n_2A + n_2B);
+        mean__2B = mean__2A - quality;
+      }
+    }
+    else {
+      if (zone1_ok) {
+        mean__1A = (mean_1 * (double) (n_1A + n_1B) - (double) n_1B * quality) / (double) (n_1A + n_1B);
+        mean__1B = mean__1A + quality;
+      }
+      if (zone2_ok) {
+        mean__2A = (mean_2 * (double) (n_2A + n_2B) - (double) n_2B * quality) / (double) (n_2A + n_2B);
+        mean__2B = mean__2A + quality; 
+      }
+    }
+
+    // calculate luminance variations
+    if (zone1_ok) {
+      var_1A = rint(mean__1A - mean_1A);
+      var_1B = rint(mean__1B - mean_1B);
+    }
+    else var_1A = var_1B = 0;
+    
+    if (zone2_ok) {
+      var_2A = rint(mean__2A - mean_2A);
+      var_2B = rint(mean__2B - mean_2B);
+    }
+    else var_2A = var_2B = 0;
+
+    if (verbose > 2) {
+      if (zone1_ok)
+        fprintf(stderr, "m*_1A = %lf, m*_1B = %lf\n", mean__1A, mean__1B);
+      if (zone2_ok)
+        fprintf(stderr, "m*_2A = %lf, m*_2B = %lf\n", mean__2A, mean__2B);
+      fprintf(stderr, "var %d %d %d %d\n", var_1A, var_1B, var_2A, var_2B);
+    }
+
+    // apply luminance variations to image pixels
+    for (i = 0; i < blocksize; i++)
+      for (j = 0; j < blocksize; j++) {
+        int pixel = image[yb * blocksize + j][xb * blocksize + i];
+        int pixel_zone = zone[j][i];
+        int pixel_category = CATEGORY_VOID;
+        if (pixel_zone == ZONE_1)
+          pixel_category = category1[j][i];
+        else if (pixel_zone == ZONE_2)
+          pixel_category = category2[j][i];
+
+        switch (pixel_zone | pixel_category) {
+          case CLASSIFICATION_1A:
+            pixel = GRAYRANGE(pixel + var_1A);
+            break;
+          case CLASSIFICATION_1B:
+            pixel = GRAYRANGE(pixel + var_1B);
+            break;
+          case CLASSIFICATION_2A:
+            pixel = GRAYRANGE(pixel + var_2A);
+            break;
+          case CLASSIFICATION_2B:
+            pixel = GRAYRANGE(pixel + var_2B);
+            break;
+        }
+        image[yb * blocksize + j][xb * blocksize + i] = pixel;
+      }
+
+    n++;      
+  }
+
+  free_grays(category2);
+  free_grays(category1);
+  free_grays(zone);
+  free_grays(block);
+
+  // write output image dimensions to output file
+  pgm_writepgminit(out, cols, rows, maxval, 0);
+
+  // write output image
+  for (row = 0; row < rows; row++)
+    pgm_writepgmrow(out, image[row], cols, maxval, 0);
+
+  fclose(out);
+
+  pgm_freearray(image, rows);
+
+  exit(0);
+}