--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Meerwald-dir/dwt_util.c	Fri Dec 20 13:08:59 2024 +0100
@@ -0,0 +1,159 @@
+#include "wm.h"
+#include "dwt_util.h"
+#include <ctype.h>
+
+void copy_coeffs_from_dwt(double ** block_coeffs, double ** dwt_coeffs,
+int level, int band, int width, int height) {
+  int i, j;
+  int size = width >> level;
+  int h = (band > 2) ? size : 0;
+  int w = (band & 1) ? 0 : size;
+
+  for (i = 0; i < size; i++)
+    for (j = 0; j < size; j++)
+      block_coeffs[i][j] = dwt_coeffs[h + i][w + j];
+}
+
+void copy_coeffs_to_dwt(double ** dwt_coeffs, double ** block_coeffs,
+int level, int band, int width, int height) {
+  int i, j;
+  int size = width >> level;
+  int h = (band > 2) ? size : 0;
+  int w = (band & 1) ? 0 : size;
+
+  for (i = 0; i < size; i++)
+    for (j = 0; j < size; j++)
+      dwt_coeffs[h + i][w + j] = block_coeffs[i][j];
+}
+
+char *subband_name(int type) {
+  switch (type) {
+    case LL: return "LL";
+    case HL: return "HL";
+    case LH: return "LH";
+    case HH: return "HH";
+    default: return "XX";
+  }
+}
+
+int subband_in_list(char *list, int type, int level) {
+  return 1;
+}
+
+int subband_wp_in_list(char *list, char *name) {
+  return 1;
+}
+
+int calc_subband_wp_level(char *name){
+  return strlen(name);
+}
+
+void calc_subband_location(int cols, int rows, int type, int level, int *col, int *row) {
+  *col = *row = 0;
+
+  if (level <= 0 || level > find_deepest_level(cols, rows) - 1) return;
+
+  switch (type) {
+    case LL:
+      break;
+    case HL:
+      *col = 0;
+      *row = rows >> level;
+      break;
+    case LH:
+      *col =  cols >> level;
+      *row = 0;
+      break;
+    case HH:
+      *col = cols >> level;
+      *row = rows >> level;
+      break;
+    default:
+      break;
+  }
+}
+
+void calc_subband_wp_location(int cols, int rows, char *name, int *col, int *row) {
+  char *p = name;
+  int level = 0;
+  *col = *row = 0;
+
+  while (*p) {
+    level++;
+    switch (toupper(*p)) {
+      case 'A':
+        break;
+      case 'H':
+        *col += (cols >> level);
+        break;
+      case 'V':
+        *row += (rows >> level);
+        break;
+      case 'D':
+        *col += (cols >> level);
+        *row += (rows >> level);
+        break;
+      default:
+        break;
+    }
+    p++;
+  }
+}
+
+Pixel *get_dwt_data(Image_tree dwt, int level, int type) {
+  return get_dwt_image(dwt, level, type)->data;
+}
+
+Image get_dwt_image(Image_tree dwt, int level, int type) {
+  return get_dwt_subband(dwt, level, type)->image;
+}
+
+Image_tree get_dwt_subband(Image_tree dwt, int level, int type) {
+  while (--level)
+    dwt = dwt->coarse;
+
+  switch (type) {
+    case LL: 
+      return dwt->coarse;
+    case HL: 
+      return dwt->vertical;
+    case LH: 
+      return dwt->horizontal;
+    case HH: 
+      return dwt->diagonal;
+  }
+
+  return NULL;
+}
+
+Pixel get_dwt_coeff(Image_tree dwt, int level, int type, int coeff) {
+  return get_dwt_data(dwt, level, type)[coeff];
+}
+
+Pixel get_dwt_location(Image_tree dwt, int level, int type, int col, int row) {
+  return get_pixel(get_dwt_image(dwt, level, type), col, row);
+}
+
+static void calc__subband(Image_tree p, Image_tree q, double *min, double *max, double *error) {
+  int i;
+  
+  if (!p || !q) return;
+  
+  *error = 0;
+  *min = *max = fabs(p->image->data[0] - q->image->data[0]);
+  for (i = 0; i < p->image->size; i++) {
+    double diff = fabs(p->image->data[i] - q->image->data[i]);
+    
+    *error += sqr(diff);
+    if (diff < *min) *min = diff;
+    if (diff > *max) *max = diff;
+  }
+}
+
+void calc_subband(Image_tree p, Image_tree q, int type, double *min, double *max, double *error) {
+  calc__subband(p, q, min, max, error);
+}
+
+void calc_subband_wp(Image_tree p, Image_tree q, char *name, double *min, double *max, double *error) {
+  calc__subband(p, q, min, max, error);
+}