clear all;

close all;

warning off all;

I = imread(;lena.bmp;); %%如果是其他型別影象,請先轉換為灰度圖

%%沒有噪聲時的檢測結果

BW_sobel = edge(I,;sobel;);

BW_prewitt = edge(I,;prewitt;);

BW_roberts = edge(I,;roberts;);

BW_laplace = edge(I,;log;);

BW_canny = edge(I,;canny;);

figure(1);

subplot(2,3,1),imshow(I),xlabel(;原始影象;);

subplot(2,3,2),imshow(BW_sobel),xlabel(;sobel檢測;);

subplot(2,3,3),imshow(BW_prewitt),xlabel(;prewitt檢測;);

subplot(2,3,4),imshow(BW_roberts),xlabel(;roberts檢測;);

subplot(2,3,5),imshow(BW_laplace),xlabel(;laplace檢測;);

subplot(2,3,6),imshow(BW_canny),xlabel(;canny檢測;);

%%加入高斯噪聲（μ=0，σ^2=0.01）檢測結果

I_g1 = imnoise(I,;gaussian;,0,0.01);

BW_sobel = edge(I_g1,;sobel;);

BW_prewitt = edge(I_g1,;prewitt;);

BW_roberts = edge(I_g1,;roberts;);

BW_laplace = edge(I_g1,;log;);

BW_canny = edge(I_g1,;canny;);

figure(2);

subplot(2,3,1),imshow(I_g1),xlabel(;加入高斯噪聲(μ=0，σ^2=0.01)影象;);

subplot(2,3,2),imshow(BW_sobel),xlabel(;sobel檢測;);

subplot(2,3,3),imshow(BW_prewitt),xlabel(;prewitt檢測;);

subplot(2,3,4),imshow(BW_roberts),xlabel(;roberts檢測;);

subplot(2,3,5),imshow(BW_laplace),xlabel(;laplace檢測;);

subplot(2,3,6),imshow(BW_canny),xlabel(;canny檢測;);

%%加入高斯噪聲（μ=0，σ^2=0.02）檢測結果

I_g2 = imnoise(I,;gaussian;,0,0.02);

BW_sobel = edge(I_g2,;sobel;);

BW_prewitt = edge(I_g2,;prewitt;);

BW_roberts = edge(I_g2,;roberts;);

BW_laplace = edge(I_g2,;log;);

BW_canny = edge(I_g2,;canny;);

figure(3);

subplot(2,3,1),imshow(I_g2),xlabel(;加入高斯噪聲(μ=0，σ^2=0.02)影象;);

subplot(2,3,2),imshow(BW_sobel),xlabel(;sobel檢測;);

subplot(2,3,3),imshow(BW_prewitt),xlabel(;prewitt檢測;);

subplot(2,3,4),imshow(BW_roberts),xlabel(;roberts檢測;);

subplot(2,3,5),imshow(BW_laplace),xlabel(;laplace檢測;);

subplot(2,3,6),imshow(BW_canny),xlabel(;canny檢測;);