%% Read imageclearf = im2double(imread('Fig1006(a)(building).tif'));%% Display imageimshow(f,[]);title('Original image');pause%% Edge Detection% [g, t] = edge(f, 'method', parameters);%% Sobel Edge Detection % automatic threshold[v, t] = edge(f, 'sobel' , 'vertical');imshow(v);title(sprintf('Sobel Edge Dectection [auto vertical t = %0.2f]',t));pause% manual thresholdt = 0.15;v = edge(f, 'sobel', t, 'vertical');imshow(v);title(sprintf('Sobel Edge Dectection [manual vertical t = %0.2f]',t));pause% Sobel edge +45 degreew = [-2 -1 0; -1 0 1; 0 1 2];v = imfilter(f, w, 'replicate');t = 0.3*max(abs(v(:)));v = v >= t;imshow(v);title(sprintf('Sobel Edge Dectection [manual +45 t = %0.2f]',t));pause% Sobel edge -45 degreew = [0 1 2; -1 0 1; -2 -1 0];v = imfilter(f, w, 'replicate');t = 0.3*max(abs(v(:)));v = v >= t;imshow(v);title(sprintf('Sobel Edge Dectection [manual -45 t = %0.2f]',t));pause%% Other methods% Sobelv0 = edge(f, 'sobel');imshow(v0);title('Sobel Edge Dectection [auto]');pause% Prewittv1 = edge(f, 'prewitt');imshow(v1);title('Prewitt Edge Dectection [auto]');pause% Robertsv2 = edge(f, 'roberts');imshow(v2);title('Roberts Edge Dectection [auto]');pause% Laplacian of Gaussian Methodv3 = edge(f, 'log');imshow(v3);title('Laplacian of Gaussian Method [auto]');pause% Zero-crossv4 = edge(f, 'zerocross');imshow(v4);title('Zero-cross Method [auto]');pause% Cannyv5 = edge(f, 'canny');imshow(v5);title('Canny Edge Dectection [auto]');pausesubplot(231);imshow(v0);title('Sobel Edge Dectection [auto]');subplot(232);imshow(v1);title('Prewitt Edge Dectection [auto]');subplot(233);imshow(v2);title('Roberts Edge Dectection [auto]');subplot(234);imshow(v3);title('Laplacian of Gaussian Method [auto]');subplot(235);imshow(v4);title('Zero-cross Method [auto]');subplot(236);imshow(v5);title('Canny Edge Dectection [auto]');