close all
clear
clc
disp('====E4_7_4.m====');

I=imread('liftingbody.png');
subplot(2,3,1),imshow(I),xlabel('(a)ԭʼͼÏñ');

J=imnoise(I,'salt & pepper',0.06);
subplot(2,3,2),imshow(J),xlabel('(b)ÔëÉùͼÏñ');

K1=filter2(fspecial('average',3),J);
subplot(2,3,3),imshow(uint8(K1)),xlabel('(c)3*3Ä£°å¾ùÖµÂ˲¨');

mask1=[0 1 0
       1 0 1
       0 1 0];
mask1=(1/2)*mask1;   % Óï¾ä1
K2=filter2(mask1,J);
subplot(2,3,4),imshow(uint8(K2)),xlabel('(d)4ÁÚÓòÄ£°å¾ùÖµÂ˲¨');

mask2=[1 1 1
       1 0 1
       1 1 1];
mask2=(1/16)*mask2;    % Óï¾ä2
K3=filter2(mask2,J);
subplot(2,3,5),imshow(uint8(K3)),xlabel('(e)8ÁÚÓòÄ£°å¾ùÖµÂ˲¨');

mask3=[1 2 1
       2 4 2
       1 2 1];
mask3=(1/16)*mask3;
K4=filter2(mask3,J);
subplot(2,3,6),imshow(uint8(K4)),xlabel('(f)¸ß˹ģ°å¾ùÖµÂ˲¨');