amle_init.c

image processing including fourier,wavelet,segmentation etc.

/*--------------------------- Commande MegaWave -----------------------------*/
/* mwcommand
  name = {amle_init};
  version = {"1.1"};
  author = {"Jacques Froment"};
  function = {"Compute initial data for the level line image interpolation scheme (AMLE)"};
  usage = {
  in->in
         "Input uniformly quantized fimage",
  delta->delta
         "Width step of the uniform quantization used for the input image",
  out<-out
         "Output fimage as initial data (input) for the AMLE model"
  };
*/
/*--- MegaWave - Copyright (C) 1992 Jacques Froment. All Rights Reserved. ---*/

#include <stdio.h>
#include "mw.h"

/* Compute the 4 neighbour pixels of the current pixel p              */
/* When p touches the border of the image, a mirror effect is applied */

void neighbor_4(x,y,xmax,ymax,p,left,right,up,down)

register int x,y,xmax,ymax;
register float *p;
float **left,**right,**up,**down;
{
  if (x>0)
    {
      *left = p-1;
      if (x < xmax)
        {
          *right = p+1;
          if (y>0)
            {
              *up =p-xmax-1;
              if (y < ymax)
                /* 0 < x < xmax  0 < y < ymax */
		*down=p+xmax+1;
              else /* 0 < x < xmax   y = ymax */
		*down=*up;
            }
          else /* 0 < x < xmax   y = 0 */
            {
              *down= p+xmax+1;
              *up=*down;
            }
        }
      else /* x = xmax */
        {
          *right=*left;
          if (y>0)
            {
              *up=p-xmax-1;
              if (y < ymax)
		/* x = xmax  0 < y < ymax */
		*down=p+xmax+1;
              else /* x = xmax   y = ymax */
		*down=*up;
            }
          else /* x = xmax  y = 0 */
            {
              *down=p+xmax+1;
              *up=*down;
            }
        }
    }
  else /* x = 0 */
    {
      *right=p+1;
      *left=*right;
      if (y>0)
        {
          *up=p-xmax-1;
          if (y < ymax)
	    /* x = 0  0 < y < ymax */
	    *down=p+xmax+1;
          else /* x = 0   y = ymax */
	    *down=*up;
        }
      else /* x = 0   y = 0 */
        {
          *down=p+xmax+1;
          *up=*down;
        }
    }
}

void amle_init(in,delta,out)

Fimage in,out;
float delta;

{ 
  int NC,NL,x,y;
  register float *I,*O;
  float *left,*right,*up,*down;
  float Max;

  if (in==NULL) mwerror(FATAL,1,"Null input fimage.\n");

  NL=in->nrow;
  NC=in->ncol;

  out = mw_change_fimage(out,NL,NC);
  if (out == NULL) mwerror(FATAL,1,"Not enough memory.\n");

  mw_clear_fimage(out,0.0);

  I = in->gray;
  O = out->gray;
  
  for (y=0; y<NL; y++)
    for (x=0; x<NC; x++, I++,O++)
      {
	neighbor_4(x,y,NC-1,NL-1,I,&left,&right,&up,&down);
	if ((*I != *left) || (*I != *right) || (*I != *up) || (*I != *down))
	  {
	    Max = *I;
	    if (*left > Max) Max=*left;
	    if (*right > Max) Max=*right;
	    if (*up > Max) Max=*up;
	    if (*down > Max) Max=*down;

	    if (*I < Max) *O = *I + delta;
	    else *O = *I;
	  }
      }
}