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From: fang@dukempd.phy.duke.edu (Fang Zhong)
Newsgroups: comp.sys.ibm.pc.programmer
Subject: Help needed
Message-ID: <866@dukempd.phy.duke.edu>
Date: 9 Apr 90 08:05:10 GMT
Organization: Duke University Physics Dept.; Durham, N.C.
Lines: 103


	I am doing some image processing on a IBM PC-AT.
I use subroutines from ImageTool by Werner Frei Associates
to grab images.  I want to average several frames on an
image to increase S/N ratio.  I wrote a program with MS
QuickC 2.0 (enclosed below).  It takes 75 seconds to just
average over two frames.  Normally I want to average at
least eight frames.  That would take ten minutes during
which my image pattern may have changed.  
	Can some experts on the net tell me how to improve
the speed of the averaging through better programing?
	Thanks in advance.

Fang


-----------------------------------------------------
#include <stdio.h>
#include <malloc.h>
include "imtool.h" 

#define row 480
#define col 512

int **imatrix();
void free_imatrix();

int **ival;

void main()
{
	long ms, crg;
	int mode = 1, num, nframe, i, j, k, pval;

	ival = imatrix(1, row, 1, col);  /* allocate memory for ival */

	for(k = 1; k <= row; k++) {          /* initialize ival */
		for(j = 1; j <= col; j++) {
			ival[k][j] = 0;
		}
	}

	/* initialize imtool routines */
	ms = 0xd000;
	crg = 0x300;
	num = 1;
	INITIM(&num,&ms,&crg);    /* initialize the Frame Grabber Board */
	BRDSEL(&num);             /* initialize selected board */
	CLKSEL(&num);             /* initialize Clock mode to be PLL */

	printf("How many frames do you want to average?\n");
	scanf("%d", &nframe);

	for(i = 0; i < nframe; ++i) {
		DIGITZ(&mode);
		printf("\aCollecting frame #%d\n", i+1);
		for(k = 0; k < row; ++k) {
			for(j = 0; j < col; ++j) {
				RDPXL(&j, &k, &pval);
				ival[k+1][j+1] += pval;
			}
		}
	}

	printf("\aDisplay averaged image\n");

	for(k = 0; k < row; ++k) {
		for(j = 0; j < col; ++j) {
			pval = ival[k+1][j+1] / nframe;
			WRPXL(&j, &k, &pval);
			}
	}
	free_imatrix(ival, 1, row, 1, col);
}

int **imatrix(nrl,nrh,ncl,nch)
int nrl,nrh,ncl,nch;
{
	int i,**m;

	m=(int **)malloc((unsigned) (nrh-nrl+1)*sizeof(int*));
	m -= nrl;

	for(i=nrl;i<=nrh;i++) {
		m[i]=(int *)malloc((unsigned) (nch-ncl+1)*sizeof(int));
		m[i] -= ncl;
	}
	return m;
}

void free_imatrix(m,nrl,nrh,ncl,nch)
int **m;
int nrl,nrh,ncl,nch;
{
	int i;

	for(i=nrh;i>=nrl;i--) free((char*) (m[i]+ncl));
	free((char*) (m+nrl));
}
-- 
	Fang Zhong				1-919-684-8247
	Duke University Dept. of Physics	fang@phy.duke.edu
	Durham, N.C.      27706