/* noise.c */
#include <stdio.h>
#include <stdlib.h>  
#include <malloc.h>
#include <math.h>
#include <time.h>
#define	 IX 256
#define	 IY 256
#define	 PI	3.141592
void main( void )
{
    FILE		*fpr,*fpw;
    FILE		*fopen();
    unsigned char	*ip;
    double		t, data;
    int			bip, i, j;
	ip   = (unsigned char *)malloc( IX*IY, sizeof(unsigned char) );

/*	NOTE!! (j:suffix for row, i:suffix for column) */

    fpr = fopen("myarea.gray","rb");
    fpw = fopen("noised.gray","wb");
	fread(ip,IX*IY*sizeof(unsigned char),1,fpr);

	t = 1.0/IX;          /* Period of signal */
 
	for (j=0; j < IY; j++){
		data = 0.0;
		for (i=0; i < IX; i++){
			data = ip[i] + 40.0* cos(2*PI * 34*t * i) +
		          20.0 * sin(2*PI * 65*t * j);
			bip = data;
			if (bip > 255) bip = 255;
			if (bip < 0  ) bip = 0;
			fputc(bip,fpw);
		}
		ip += IX;
	}
	fclose(fpr);
    fclose(fpw);
}