MATLAB-使用没有IMFILTER功能的5x5滤波器的图像过滤

Question

我试图修改代码(在MATLAB中实现Imfilter(以使用5x5高斯滤波器过滤图像。有问题，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

如果我使用Imshow显示图片，如果我使用Imfilter函数，则看起来有所不同。谁能帮忙？

Answer 1

首先，将图像转换为double，然后执行剩余过程。请参阅下面的示例代码：

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