frthre.c

image processing including fourier,wavelet,segmentation etc.

/*--------------------------- MegaWave2 module -----------------------------*/
/* mwcommand
 name = {frthre};
 author = {"Jacques Froment"};
 version = {"1.0"};
 function = {"Thresold the pixel's gray-levels of a noisy fimage for optimal recovery"};
 usage = {
 'l':[noise=20.0]->noise    "Absolute value of the additive noise",
 fimage->A    "Input fimage", 
 result<-B    "Output image"
};
*/
/*--------------------------------------------------------------------------*/

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

void frthre(A,B,noise)

Fimage	A,B;
float *noise;

{
  register float *ptrA,*ptrB;
  register int i;
  
  if ((B = mw_change_fimage(B,A->nrow,A->ncol)) == NULL)
    mwerror(FATAL, 1, "Not enough memory !\n");  
  
  for (ptrA=A->gray, ptrB=B->gray, i=0;  i < A->nrow*A->ncol; 
       ptrA++, ptrB++, i++) 
    {
      if (*ptrA > *noise) 
	  *ptrB = *ptrA - *noise;
      else 
	if (*ptrA < - *noise)
	  *ptrB = *ptrA + *noise;
	else
	  *ptrB = 0.0;
    }
}