fmi_image_filter.c

 
#include <math.h> 
#include "fmi_util.h"
#include "fmi_image.h"
#include "fmi_image_filter.h"
 
void detect_vert_gradient(FmiImage *source, FmiImage *trace)
{
  int i, j, k;
  int j_upper, j_lower;
  int g;
  canonize_image(source, trace);
 
  for (k = 0; k < source->channels; k++) {
    for (j = 0; j < source->height; j++) {
      j_upper = j - 1;
      j_lower = j + 1;
      for (i = 0; i < source->width; i++) {
        g = (get_pixel(source, i, j_upper, k)
            - get_pixel(source, i, j_lower, k)) / 2 + 128;
        if (g > 254)
          g = 254;
        if (g < 2)
          g = 2;
        put_pixel(trace, i, j, k, g);
      }
    }
  }
}
 
void detect_horz_gradient(FmiImage *source, FmiImage *trace)
{
  int i, j, k;
  int i_left, i_right;
  int g;
  canonize_image(source, trace);
 
  for (k = 0; k < source->channels; k++) {
    for (i = 0; i < source->width; i++) {
      i_left = i - 1;
      i_right = i + 1;
      for (j = 0; j < source->height; j++) {
        g = (get_pixel(source, i_right, j, k) - get_pixel(source, i_left, j, k)) / 2 + 128;
        if (g > 254)
          g = 254;
        if (g < 2)
          g = 2;
        put_pixel(trace, i, j, k, g);
      }
    }
  }
}
 
 
void detect_vert_maxima(FmiImage *source,FmiImage *trace){
    int i,j,k;
    Byte g,g_upper,g_lower,gmax;
    canonize_image(source,trace);
    /*check_image_properties(source,trace); */
 
    for (k=0;k<source->channels;k++){
        for (j=1;j<source->height-1;j++){
            for (i=0;i<source->width;i++){
                g = get_pixel(source,i,j,k);
                g_upper = get_pixel(source,i,j-1,k);
                g_lower = get_pixel(source,i,j+1,k);
                gmax = MAX(g_upper,g_lower);
                /*put_pixel(trace,i,j,k,gmax); */
                if (g>gmax)
                    put_pixel(trace,i,j,k,(Byte)(g-gmax));
                else
                    put_pixel(trace,i,j,k,0);
            }
        }
    }
}
 
/* calculate RELATIVE "shoulder", 242 => 2   393 => 3 , divide by should avg */
void detect_vert_maxima2(FmiImage *source, FmiImage *trace)
{
  int i, j, k;
  Byte g, g_sum; /*g_upper,g_lower; */
  int gt;
  canonize_image(source, trace);
  /*check_image_properties(source,trace); */
 
  for (k = 0; k < source->channels; k++) {
    for (j = 1; j < source->height - 1; j++) {
      for (i = 0; i < source->width; i++) {
        g = get_pixel(source, i, j, k);
        /*  g_upper=get_pixel(source,i,j-1,k);
         g_lower=get_pixel(source,i,j+1,k);
         gt=(2*g-g_upper-g_lower)/(1+g_upper+g_lower);
         */
        g_sum = (get_pixel(source, i, j - 1, k)
            + get_pixel(source, i, j + 1, k));
        gt = (2 * g - g_sum) / (1 + g_sum);
        gt = MAX(0,gt);
        /*  gt=pseudo_sigmoid(128,gt); */
        put_pixel(trace, i, j, k, gt);
      }
    }
  }
}
 
void detect_horz_edges(FmiImage *source, FmiImage *trace)
{
  int i, j, k;
  int g, g2;
  canonize_image(source, trace);
  /*check_image_properties(source,trace); */
 
  for (k = 0; k < source->channels; k++) {
    for (j = 1; j < source->height - 1; j++) {
      for (i = 0; i < source->width; i++) {
        g = get_pixel(source, i, j, k) - get_pixel(source, i, j - 1, k);
        g2 = get_pixel(source, i, j, k) - get_pixel(source, i, j + 1, k);
        g = MAX(g,g2);
        g = MAX(0,g);
        put_pixel(trace, i, j, k, g);
      }
    }
  }
  if (FMI_DEBUG(3))
    write_image("edges", trace, PGM_RAW);
}
 
void detect_horz_maxima(FmiImage *source, FmiImage *trace)
{
  int i, j, k;
  unsigned char g, g_left, g_right, gmax, gt;
  canonize_image(source, trace);
 
  for (k = 0; k < source->channels; k++) {
    for (i = 1; i < source->width - 1; i++) {
      for (j = 0; j < source->height; j++) {
        g = get_pixel(source, i, j, k);
        g_left = get_pixel(source, i - 1, j, k);
        g_right = get_pixel(source, i + 1, j, k);
        gmax = MAX(g_left,g_right);
        if (g > gmax) {
          gt = get_pixel(trace, i, j, k);
          put_pixel(trace, i, j, k, MAX(gt,g-gmax));
        }
        /*  else */
        /*  put_pixel(trace,i,j,k,0); */
      }
    }
  }
}
 
void detect_vert_edges(FmiImage *source,FmiImage *trace){
  int i,j,k;
  int g,g2;
  canonize_image(source,trace);
  /*check_image_properties(source,trace); */
 
  for (k=0;k<source->channels;k++){
    for (i=1;i<source->width-1;i++){
     for (j=0;j<source->height;j++){
       g =get_pixel(source,i,j,k)-get_pixel(source,i-1,j,k);
       g2=get_pixel(source,i,j,k)-get_pixel(source,i+1,j,k);
       g=MAX(g,g2);
       g=MAX(0,g);
       put_pixel(trace,i,j,k,g);}
    }
  }
  if (FMI_DEBUG(5)) write_image("debug_edges",trace,PGM_RAW);
}
 
void iir_right(FmiImage *source, FmiImage *trace, int promille)
{
  int i, j, k;
  int g, g_old;
  canonize_image(source, trace);
  for (k = 0; k < source->channels; k++)
    for (j = 0; j < source->height; j++) {
      g_old = 0;
      for (i = 0; i < source->width; i++) {
        g = get_pixel(source, i, j, k);
        g = MAX(g,g_old);
        put_pixel(trace, i, j, k, g);
        g_old = g * promille / 1000;
      }
    }
  if (FMI_DEBUG(5))
    write_image("debug_iir_right", trace, PGM_RAW);
}
 
void iir_left(FmiImage *source, FmiImage *trace, int promille)
{
  int i, j, k;
  int g, g_old;
  canonize_image(source, trace);
  for (k = 0; k < source->channels; k++)
    for (j = 0; j < source->height; j++) {
      g_old = 0;
      for (i = source->width - 1; i >= 0; i--) {
        g = get_pixel(source, i, j, k);
        g = MAX(g,g_old);
        put_pixel(trace, i, j, k, g);
        g_old = g * promille / 1000;
      }
    }
  if (FMI_DEBUG(5))
    write_image("debug_iir_left", trace, PGM_RAW);
}
 
void iir_up(FmiImage *source, FmiImage *trace, int promille)
{
  int i, j, k;
  int g, g_old;
  canonize_image(source, trace);
  for (k = 0; k < source->channels; k++)
    for (i = 0; i < source->width; i++) {
      g_old = 0;
      for (j = 0; j < source->height; j++) {
        g = get_pixel(source, i, j, k);
        g = MAX(g,g_old);
        put_pixel(trace, i, j, k, g);
        g_old = g * promille / 1000;
      }
    }
  if (FMI_DEBUG(5))
    write_image("debug_iir_up", trace, PGM_RAW);
}
 
void iir_down(FmiImage *source, FmiImage *trace, int promille)
{
  int i, j, k;
  int g, g_old;
  canonize_image(source, trace);
  for (k = 0; k < source->channels; k++)
    for (i = 0; i < source->width; i++) {
      g_old = 0;
      for (j = source->height - 1; j >= 0; j--) {
        g = get_pixel(source, i, j, k);
        g = MAX(g,g_old);
        put_pixel(trace, i, j, k, g);
        g_old = g * promille / 1000;
      }
    }
  if (FMI_DEBUG(5))
    write_image("debug_iir_down", trace, PGM_RAW);
}
 
void mask_image(FmiImage *source, FmiImage *mask, Byte threshold, Byte c)
{
  register int i;
  check_image_properties(source, mask);
  if (FMI_DEBUG(3))
    image_info(source);
 
  for (i = 0; i < source->volume; i++)
    if (mask->array[i] < threshold)
      source->array[i] = c;
 
}
 
void threshold_image(FmiImage *source,FmiImage *target,Byte threshold){
  register int i;
  Byte c;
  for (i=0;i<source->volume;i++){
    c=source->array[i];
    target->array[i]=(c>threshold)?c:0;
  }
}
 
void binarize_image(FmiImage *source,FmiImage *target,Byte c){
  register int i;
  for (i=0;i<source->volume;i++)
    target->array[i]=(source->array[i]>c)?255:0;
}
 
#define MAXVAL 250
void propagate_right(FmiImage *source, FmiImage *domain, FmiImage *target,
  signed char slope, void(* put_func)(FmiImage *, int, int, int, Byte))
{
  register int i, j, k;
  int c;
 
  check_image_properties(domain, target);
  if (source != NULL)
    check_image_properties(domain, source);
  for (k = 0; k < domain->channels; k++) {
    for (j = 0; j < domain->height; j++) {
      c = 0;
      for (i = 0; i < domain->width; i++) {
        /*for (i=1;i<domain->width-1;i++){ */
        /*  printf("\nDomain (%d,%d)=%d ",i,j,get_pixel(domain,i,j,k)) ; */
        if (((int) get_pixel(domain, i, j, k)) > 0) {
          if (c == 0) {
            /*  printf("N "); */
            if (source != NULL) {
              c = (int) get_pixel(source, i, j, k);
              if (c == 0)
                c = 1;
            } else
              c = 1;
          } else {
            c = c + slope;
            if (c > MAXVAL)
              c = MAXVAL - 1;
            if (c < 1)
              c = 1;
          }
        } else
          c = 0;
        /*  c2=get_pixel(target,i,j,k); c=MAX(c,c2); */
        put_func(target, i, j, k, (Byte) c);
      }
    }
  }
}
 
void propagate_left(FmiImage *source, FmiImage *domain, FmiImage *target,
  signed char slope, void(* put_func)(FmiImage *, int, int, int, Byte))
{
  register int i, j, k;
  int c;
 
  for (k = 0; k < domain->channels; k++) {
    for (j = 0; j < domain->height; j++) {
      c = 0;
      for (i = domain->width - 1; i >= 0; i--) {
        /*for (i=domain->width-2;i>0;i--){ */
        if (((int) get_pixel(domain, i, j, k)) > 0) {
          if (c == 0) {
            /* START MARKER MODE ... */
            if (source != NULL) {
              c = (int) get_pixel(source, i, j, k); /* ... with local start value */
              if (c == 0)
                c = 1;
            } else
              c = 1;
          } /* ... with value 1 */
          else {
            /* CONTINUE MARKER MODE  */
            c = c + slope;
            if (c > MAXVAL)
              c = MAXVAL - 2;
            if (c < 1)
              c = 1;
          }
        } else
          /* domain==0 */
          c = 0; /* RETURN TO SEARCH MODE */
        /*c2=get_pixel(target,i,j,k);   c=MAX(c,c2); */
        put_func(target, i, j, k, (Byte) c);
      }
    }
  }
}
 
void propagate_up(FmiImage *source, FmiImage *domain, FmiImage *target,
  signed char slope, void(* put_func)(FmiImage *, int, int, int, Byte))
{
  register int i, j, k;
  int c;
 
  for (k = 0; k < domain->channels; k++) {
    for (i = 0; i < domain->width; i++) {
      c = 0;
      for (j = 0; j < domain->height; j++) {
        if (get_pixel(domain, i, j, k) > 0) {
          if (c == 0) {
            if (source != NULL) {
              c = get_pixel(source, i, j, k);
              if (c == 0)
                c = 1;
            } else
              c = 1;
          } else {
            c = c + slope;
            if (c > MAXVAL)
              c = MAXVAL - 3;
            if (c < 1)
              c = 1;
          }
        } else
          c = 0;
        /* c2=get_pixel(target,i,j,k); c=MAX(c,c2); */
        put_func(target, i, j, k, (unsigned char) c);
      }
    }
  }
}
 
void propagate_down(FmiImage *source, FmiImage *domain, FmiImage *target,
  signed char slope, void(* put_func)(FmiImage *, int, int, int, Byte))
{
  register int i, j, k;
  int c;
 
  for (k = 0; k < domain->channels; k++) {
    for (i = 0; i < domain->width; i++) {
      c = 0;
      for (j = domain->height - 1; j >= 0; j--) {
        if (get_pixel(domain, i, j, k) > 0) {
          if (c == 0) {
            if (source != NULL) {
              c = get_pixel(source, i, j, k);
              if (c == 0)
                c = 1;
            } else
              c = 1;
          } else {
            c = c + slope;
            if (c > MAXVAL)
              c = MAXVAL - 4;
            if (c < 1)
              c = 1;
          }
        } else
          c = 0;
        /*c2=get_pixel(target,i,j,k);   c=MAX(c,c2); */
        put_func(target, i, j, k, (unsigned char) c);
      }
    }
  }
}
   
 
 
void horz_seg_lengths(FmiImage *source, FmiImage *target)
{
  propagate_right(NULL, source, target, 1, put_pixel);
  if (FMI_DEBUG(5))
    write_image("debug_horz_seg_lengths_1", target, PGM_RAW);
  propagate_left(target, source, target, 0, put_pixel);
  if (FMI_DEBUG(4))
    write_image("debug_horz_seg_lengths", target, PGM_RAW);
}
 
void vert_seg_lengths(FmiImage *source, FmiImage *target)
{
  propagate_up(NULL, source, target, 1, put_pixel);
  if (FMI_DEBUG(5))
    write_image("debug_vert_seg_lengths_1", target, PGM_RAW);
  propagate_down(target, source, target, 0, put_pixel);
  if (FMI_DEBUG(4))
    write_image("debug_vert_seg_lengths", target, PGM_RAW);
}
 
void row_statistics(FmiImage *source, Byte *nonzero, Byte *avg, Byte *pow)
{
  register int i, j;
  int nz, s;
  long int s2;
  Byte c;
  for (j = 0; j < source->height; j++) {
    nz = 0;
    s = 0;
    s2 = 0;
    for (i = 0; i < source->width; i++) {
      c = get_pixel(source, i, j, 0);
      /*nz+=(c>0); */
      if (c > 0)
        ++nz;
      s += c;
      s2 += c * c;
    }
    /*    printf("%d nz=%d s=%d s2=%d (w=%d)\n",j,nz,s,s2,source->width); */
    if (nonzero != NULL)
      nonzero[j] = (255 * nz) / source->width;
    if (avg != NULL)
      avg[j] = s / source->width;
    if (pow != NULL)
      pow[j] = sqrt(s2 / source->width);
  }
}
 
void col_statistics(FmiImage *source, Byte *nonzero, Byte *avg, Byte *pow)
{
  register int i, j;
  int nz, s;
  long int s2;
  Byte c;
  for (i = 0; i < source->width; i++) {
    nz = 0;
    s = 0;
    s2 = 0;
    for (j = 0; j < source->height; j++) {
      c = get_pixel(source, i, j, 0);
      nz += (c > 0);
      s += c;
      s2 += c * c;
    }
    if (nonzero != NULL)
      nonzero[j] = 255 * nz / source->width;
    if (avg != NULL)
      avg[j] = s / source->width;
    if (pow != NULL)
      pow[j] = sqrt(s2 / source->width);
  }
}