高斯差分有什么用

Matlab：

clear all; 
clc
close all; 
%% Read image from file

img1 = 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');