理論知識見文章Bilateral Filtering for Gray and Color Images
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.4.634&rep=rep1&type=pdf
matlab原程序如下：
function [img1] = perform_bilateral_filtering(img,winsize,sigma)
% Bilateral Filtering(img,winsize,sigma)
% Input -> Image img
% -> winsize: spatial filter width
% -> sigma for intensity diff gaussain filter
% -> sigma for spatial filter = winsize/6
% Output -> Filtered Image
% Author: Amit Agrawal, 2004
% should be odd
winsize = round( (winsize-1)/2 )*2 + 1;
[H,W] = size(img);
%Gaussian spatial filter
g_filter = fspecial('gaussian',winsize,winsize/6);
padnum = (winsize-1)/2;
A = padarray(img,[padnum padnum],'replicate','both');
img1 = zeros(size(img));
for jj = padnum+1:(padnum+1+H-1)
for kk = padnum+1:(padnum+1+W-1)
% Get a local neighborhood
imgwin = A(jj-padnum:jj+padnum,kk-padnum:kk+padnum);
% Find weights according to intensity diffs
Wwin = exp(-abs(imgwin - imgwin(padnum+1,padnum+1))/sigma^2);
% Find composite filter
newW = Wwin.*g_filter;
t = sum(sum(newW));
if(t>0)
newW = newW/t;
end
img1(jj-padnum,kk-padnum) = sum(sum(imgwin.*newW));
end
end
列子：
I = im2double(imread(dragonfly.jpg));%讀入原圖
IL = perform_bilateral_filtering(I,10,10);%調用上述雙邊濾波函數，對原圖像I濾波，得到圖像大尺度。
ID= I -IL;%原圖像小尺度即圖像細節部分
I4 = IL 3*ID; %圖像細節部分放大3倍