cextcenter.c

image processing including fourier,wavelet,segmentation etc.

/*--------------------------- Commande MegaWave -----------------------------*/
/* mwcommand
name = {cextcenter};
author = {"Jean-Pierre D'Ales"};
function = {"Copy the center part of a cimage into another image"};
usage = {
'f':[Fact=16]->Fact
  "Factor (default:16)", 
OriginalImage->Image 
  "Input Cimage", 
CopyImage<-cextcenter
  "Output center part of the input"
};
version = {"1.00"};
 */


/*--- Include files UNIX C ---*/
#include <stdio.h>

/*--- Library megawave2 ---*/
#include  "mw.h"


Cimage
cextcenter(Fact, Image)

int            *Fact;   /* Output size must be a multiple of Fact */
Cimage          Image;	/* Original image */

{
  Cimage          Result;	    /* Resulting image */
  int             dx, dy;           /* Size of the input image */
  int             rdx, rdy;	    /* Size of the resulting image */
  int             orx, ory;	    /* Coordinates of the upper left corner 
				     * of Result in input image */
  int             l, c;		    /* Index for column and lines in images */
  register unsigned char  *ptrI, *ptrR;      /* Pointers to graylevels of Image 
				     * and Result */

  /*--- Reading of default values ---*/

  dx = Image->ncol;
  dy = Image->nrow;
  rdx = (dx / *Fact) * *Fact;
  rdy = (dy / *Fact) * *Fact;
  orx = (dx - rdx) / 2;
  ory = (dy - rdy) / 2;

  /*--- Memory allocation for resulting image ---*/

  Result = mw_new_cimage();
  if (mw_alloc_cimage(Result, rdy, rdx) == NULL)
    mwerror(FATAL, 1, "Memory allocation refused for `Result`!\n");

  /*--- Copy the extracted sub-image on result ---*/

  ptrR = Result->gray;
  ptrI = Image->gray + (ory * dx + orx);
  for (l = 0; l < rdy; l++, ptrI += dx - rdx)
    for (c = 0; c < rdx; c++, ptrI++, ptrR++)
      *ptrR = *ptrI;

  return (Result);

}