www.pudn.com > digitalimageprocessprograms.rar > jiance.m

clc; 
fid=fopen('d:/img/lena.img','r'); 
f=fread(fid,[256,256],'uchar'); 
GR=f; 
GP=f; 
GS=f; 
for x=2:255 
    for y=2:255 
        GRx(x,y)=f(x,y)-f(x+1,y+1); 
        GRy(x,y)=f(x,y+1)-f(x+1,y); 
        GR(x,y)=sqrt((GRx(x,y)).^2+(GRy(x,y)).^2); 
        GPx(x,y)=(f(x-1,y+1)+f(x,y+1)+f(x+1,y+1))/3-(f(x-1,y-1)+f(x,y-1)+f(x+1,y-1))/3; 
        GPy(x,y)=(f(x-1,y-1)+f(x-1,y)+f(x-1,y+1))/3-(f(x+1,y-1)+f(x+1,y)+f(x+1,y+1))/3; 
        GP(x,y)=sqrt((GPx(x,y)).^2+(GPy(x,y)).^2); 
        GSx(x,y)=(f(x-1,y+1)+2*f(x,y+1)+f(x+1,y+1))/3-(f(x-1,y-1)+2*f(x,y-1)+f(x+1,y-1))/3; 
        GSy(x,y)=(f(x-1,y-1)+2*f(x-1,y)+f(x-1,y+1))/3-(f(x+1,y-1)+2*f(x+1,y)+f(x+1,y+1))/3; 
        GS(x,y)=sqrt((GSx(x,y)).^2+(GSy(x,y)).^2); 
    end 
end 
subplot(2,2,1); 
imshow(f,[0,255]);title('ԭͼÏñ'); 
subplot(2,2,2); 
imshow(GR,[0,255]);title('Roberts'); 
subplot(2,2,3); 
imshow(GP,[0,255]);title('Prewitt'); 
subplot(2,2,4); 
imshow(GS,[0,255]);title('Sobel');