close all;
clear all;
i=imread('rice.tif');
BW1 = edge(i,'prewitt');
BW2 = edge(i,'canny');
BW3 = edge(i,'Roberts');
BW4 = edge(i,'log');
BW5 = edge(i,'zerocross');
BW6 = edge(i,'Sobel');

figure;imshow(BW1);title('prewitt');
figure;imshow(BW2);title('canny');
figure;imshow(BW3);title('Roberts');
figure;imshow(BW4);title('log');
figure;imshow(BW5);title('zerocross');
figure;imshow(BW6);title('Sobel');