I = imread('rice.tif');
BW1 = edge(I,'log');
% 以自動(dòng)閾值選擇法對(duì)圖像進(jìn)行Log算子檢測
[BW1,thresh1] = edge(I,'log');
% 返回當(dāng)前Log算子邊緣檢測的閾值
disp('Log算子自動(dòng)選擇的閾值為：')
disp(thresh1)
subplot(121),imshow(BW1);
title('自動(dòng)閾值的Log算子邊緣檢測')
BW1 = edge(I,'log',0.005);
% 以閾值為0.005對(duì)圖像進(jìn)行Log算子檢測
subplot(122),imshow(BW1);
title('閾值為0.005的Log算子邊緣檢測')
h=fspecial('gaussian',5);
% 設(shè)計(jì)高斯濾波器
[BW2,thresh2] = edge(I,'zerocross',[],h);
% 返回當(dāng)前零交叉檢測邊緣檢測的閾值
disp('零交叉檢測自動(dòng)選擇的閾值為：')
disp(thresh2)
figure,subplot(121),imshow(BW2);
title('自動(dòng)閾值的零交叉邊緣檢測')
BW2 = edge(I,'zerocross',0.03,h);
% 以閾值為0.03對(duì)圖像進(jìn)行零交叉檢測
subplot(122),imshow(BW2);
title('閾值為0.03的零交叉邊緣檢測')