#include "dwt_util.h"#include "wang_common.h"void init_subbands(Image_tree tree) {  int levels = 0;  int i;  Image_tree p = tree;  // determine # of detail subbands  while (p->coarse != NULL) {    levels++;    p = p->coarse;  }  // there are 3 detail subbands per level  n_subbands = 3 * levels;  // allocate memory for subband data  subbands = malloc(n_subbands * sizeof(Subband_data));  p = tree;  i = 0;  while (p->coarse != NULL) {    subbands[i++] = alloc_subband(HORIZONTAL, p->horizontal);    subbands[i++] = alloc_subband(VERTICAL, p->vertical);    subbands[i++] = alloc_subband(DIAGONAL, p->diagonal);        p = p->coarse;  }}Subband_data alloc_subband(int type, Image_tree tree) {  int i;  Subband_data p = malloc(sizeof(struct Subband_data_struct));  p->T = 0.0;  p->beta = 0.0;  p->Cmax = 0.0;  p->tree = tree;  p->level = tree->level;  p->width = tree->image->width;  p->height = tree->image->height;  p->size = p->height * p->width;  p->image = tree->image;  p->type = type;    p->selected = malloc(p->height * sizeof(char *));  p->selected[0] = calloc(p->size, sizeof(char));  for (i = 1; i < p->height; i++)    p->selected[i] = &(p->selected[0][i * p->width]);   return p;}void set_subband_beta(Subband_data subband, double beta) {  subband->beta = beta;}void set_subbands_beta(double beta) {  int i;  for (i = 0; i < n_subbands; i++)    set_subband_beta(subbands[i], beta);}void set_subbands_type_beta(int type, double beta) {  int i;  for (i = 0; i < n_subbands; i++)    if (subbands[i]->type == type)      set_subband_beta(subbands[i], beta);}void calc_subband_threshold(Subband_data subband) {  double max;  int i, j;  max = fabs(get_pixel(subband->image, 0, 0));  for (i = 0; i < subband->height; i++)    for (j = 0; j < subband->width; j++) {      Pixel p = fabs(get_pixel(subband->image, i, j));      if (p > max)        max = p;    }  subband->Cmax = max;  subband->T = max / 2.0;}void calc_subbands_threshold() {  int i;  for (i = 0; i < n_subbands; i++)    calc_subband_threshold(subbands[i]);}Subband_data select_subband() {  int max = 0;  int i;  for (i = 0; i < n_subbands; i++)    if ((subbands[i]->beta * subbands[i]->T) > (subbands[max]->beta * subbands[max]->T))      max = i;  return subbands[max];}int subband_coeff_isselected(Subband_data subband, int coeff) {  return subband->selected[0][coeff];}Pixel get_subband_coeff(Subband_data subband, int coeff) {  return subband->image->data[coeff];}void set_subband_coeff(Subband_data subband, int coeff, Pixel data) {  subband->image->data[coeff] = data;}int select_subband_coeff_from(Subband_data subband, int from) {  int i;  for (i = from; i < subband->size; i++)    if (!subband_coeff_isselected(subband, i) &&      get_subband_coeff(subband, i) > subband->T)      return i;  return -1;}int select_subband_coeff(Subband_data subband) {  select_subband_coeff_from(subband, 0);}void mark_subband_coeff(Subband_data subband, int coeff) {  subband->selected[0][coeff] = 1; }void free_subband(Subband_data subband) {  free(subband->selected[0]);  free(subband->selected);  free(subband);}void free_subbands() {  int i;    for (i = 0; i < n_subbands; i++)     free_subband(subbands[i]);  free(subbands);}#define LARGE DBL_MAXPixel figure_orig_coeff(double T, double alpha, double beta, Pixel coeff) {  int p, p_min = 0;  double dist_min = LARGE;  double sign = (coeff >= 0) ? 1.0 : -1.0;  for (p = 1; p < 1.0 / (2.0 * alpha); p++) {    double dist, delta;    delta = (1.0 + 2.0 * p * alpha) * T;    dist = fabs(delta - fabs(coeff));    if (dist < dist_min) {      dist_min = dist;      p_min = p;    }  }    if (!p_min) p_min = 1;  return sign * (1.0 + 2.0 * p_min * alpha) * T;}