yijie.txt

一阶微分算法

void Differential(BYTE *image_in, BYTE *image_out, int xsize, int ysize, float amp)
{
	int i,j,dat;
	int d[9];
	static int	cx[9]={0,0,0,0,1,-1,0,0,0};
    static int	cy[9]={0,0,0,0,1,0,0,-1,0}; 
	float xx,yy,zz;
	    
	for(j=1;j<ysize-1;j++)
	{for(i=1;i<xsize-1;i++)
	{
		
	d[0]=*(image_in+(j-1)*xsize+i-1);
	d[1]=*(image_in+(j-1)*xsize+i);
	d[2]=*(image_in+(j-1)*xsize+i+1);
	d[3]=*(image_in+(j)*xsize+i-1);
	d[4]=*(image_in+(j)*xsize+i);
	d[5]=*(image_in+(j)*xsize+i+1);
	d[6]=*(image_in+(j+1)*xsize+i-1);
	d[7]=*(image_in+(j+1)*xsize+i);
	d[8]=*(image_in+(j+1)*xsize+i+1);
	xx=(float)(cx[0]*d[0]+cx[1]*d[1]+cx[2]*d[2]+cx[3]*d[3]+cx[4]*d[4]+cx[5]*d[5]+cx[6]*d[6]+cx[7]*d[7]+cx[8]*d[8]);
		
	yy=(float)(cy[0]*d[0]+cy[1]*d[1]+cy[2]*d[2]+cy[3]*d[3]+cy[4]*d[4]+cy[5]*d[5]+cy[6]*d[6]+cy[7]*d[7]+cy[8]*d[8]);
		
	zz=(float)(amp*sqrt(xx*xx+yy*yy));
	dat=(int)zz;
	if (dat>255)
	dat=255;
		*(image_out+j*xsize+i)=dat;