Matlab影像處理(五)邊緣偵測Sobel濾波

 %% sobel邊緣濾波

close all; clear; clc;

img = double(rgb2gray(imread('Color_lena512.bmp')));

[row, col] = size(img);

Hck = [-1 -2 -1; 0 0 0; 1 2 1;];

Vck = [-1 0 1; -2 0 2; -1 0 1;];

Hfeature = zeros(row, col); Vfeature = zeros(row, col); addfeature = zeros(row, col);

H=0; V=0; s=zeros(1, row.*col);

for i=1:row-2

    for j=1:col-2

        for ii=1:3

            for jj=1:3

                H = H + img(i+ii-1, j+jj-1).*Hck(ii, jj);

                V = V + img(i+ii-1, j+jj-1).*Vck(ii, jj);

            end

        end

        Hfeature(i+1, j+1) = H;

        Vfeature(i+1, j+1) = V;

        H=0; V=0;

    end

end

count = 0;

for i=1:row

    for j=1:col

        count = count + 1;

        addfeature(i, j) = abs(Hfeature(i, j)) + abs(Vfeature(i, j));

        s(1, count) = addfeature(i, j);

    end

end

s=sort(s); min=s(1, 1); max=s(1, row.*col); outputimg = zeros(row, col);

n =@(x) ( (x-min)./(max-min) ).*255;

for i=1:row

    for j=1:col

        outputimg(i, j) = n(addfeature(i, j));

    end

end

subplot(1, 2, 1), imshow(uint8(img)), title('原圖')

subplot(1, 2, 2), imshow(uint8(outputimg)), title('sobel濾波')