Matlab-使用不帶過濾器功能的5X5過濾器進行圖像過濾

Question

我試圖修改代碼（ 在matlab中實現IMFILTER ）以使用5X5高斯濾波器對圖像進行濾波。 出了點問題，但我找不到。

     gauss_kernel = fspecial('gaussian',5,2);
        function [result] = evc_filter(input, kernel)


        rsize = size(input);

        r = zeros(rsize);

        original=padarray(input,[2,2]);

        for i = 3:rsize(1)+2
            for j = 3:rsize(2)+2           
                temp = original(i-2:i+2,j-2:j+2) .* kernel;
                r(i-2,j-2) = sum(temp(:));
            end
        end
result=r;
end

如果使用imshow顯示圖片，則使用imfilter函數時看起來會有所不同。 有人可以幫忙嗎？

Answer 1

首先，將圖像轉換為兩倍，然后執行其余步驟。 請參閱下面的示例代碼：

function imfilt()
img = imread('one.jpg');
img = double(img);
[r,c,z] = size(img);
pad = 4;
nimg = zeros(r+pad,c+pad,z);
nimg(pad/2+1: r+pad/2, pad/2+1: c+pad/2,:) = img;
h = fspecial('gaussian',5,2);

res = zeros(r,c,z);
for i = pad/2+1 : r+pad/2
    for j = pad/2+1 : c+pad/2
        tmp = nimg(i-pad/2:i+pad/2,j-pad/2:j+pad/2,1).*h;
        res(i-pad/2,j-pad/2,1) = sum(tmp(:));
        tmp = nimg(i-pad/2:i+pad/2,j-pad/2:j+pad/2,2).*h;
        res(i-pad/2,j-pad/2,2) = sum(tmp(:));
        tmp = nimg(i-pad/2:i+pad/2,j-pad/2:j+pad/2,3).*h;
        res(i-pad/2,j-pad/2,3) = sum(tmp(:));
    end
end

imshow(uint8(res),[]);
end