how can i make the result number from convolution become positive?

Question

pandu hanifa 2018-12-20

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/436649-how-can-i-make-the-result-number-from-convolution-become-positive

回答： Brian Hart 2018-12-20

在 MATLAB Online 中打开

this is the result

and this the script;

img=imread('albert.jpg');
F=size(img);
G = [0 -1 0;-1 4 -1;0 -1 0];
FxG = F;
% Konvolusi
[bf, kf] = size(F);
[bg, kg] = size(G);
m2 = floor(bg/2);
n2 = floor(kg/2);
% Penambahan elemen nol
pad = zeros(bf+4,kf+4);
pad(3:bf+2,3:kf+2) = F;
[b_pad,k_pad] = size(pad);
for i = m2+1 : b_pad-m2;
    for j = n2+1 : k_pad-n2;
        temp = 0;
        for k = -m2: m2;
            for l = -n2: n2;
                temp = temp + G(k + m2+1,l+n2+1) * pad(i-k,j-l);
            end
        end
        FxG(i,j) = temp;
        
    end
end
FxG = FxG(2:bf+3,2:kf+3);

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Brian Hart 2018-12-20

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/436649-how-can-i-make-the-result-number-from-convolution-become-positive#answer_353313

Convolution results can be negative.

If you want only positive results, two options are to either take the absolute value of the result, or find the minimum (negative) value in the result, then add its absolute value to the result (shifting all the values positive).