高斯差分有什么用

Matlab：

clear all; clcclose all; %% Read image from fileimg1 = im2double(rgb2gray(imread('e:/img/p.jpg')));[m,n,c] = size(img1); ratio = 800/(m+n); img1 = imresize(img1, ratio);  %img2 = im2double(rgb2gray(imread('e:/img/mb11.jpg')));%f=fspecial('motion', 10, 72); %img2 = imfilter(img1, f, 'replicate'); f=fspecial('gaussian',  [10,10],1.5); img2 = imfilter(img1, f, 'replicate'); f=fspecial('gaussian',[20,20],3); img3 = imfilter(img1, f, 'replicate'); figure; imshow(img1,[]); title('img1'); figure; imshow(img2,[]); title('img2'); figure; imshow(img3,[]); title('img3'); im = img1-img2;  figure; imshow(im,[]); title('im sub');