MATLAB 最大均值滤波

clear;
clc;
width=3;
xwidth=(width-1)/2;
imgn=imread('1.bmp');
imshow(imgn,[]);
imgn=double(imgn);
[m n]=size(imgn);
imgn1=imgn;
z=zeros(4,width);
tem=1;
for i=1+xwidth:1:m-xwidth
    for j=1+xwidth:1:n-xwidth     
   
        for k=-xwidth:1:xwidth
            z(1,tem)=imgn(i,j+k);
            z(2,tem)=imgn(i+k,j);
            z(3,tem)=imgn(i-k,j+k);
            z(4,tem)=imgn(i+k,j+k);
            tem=tem+1;
        end
        z1=mean(z(1,:));
        z2=mean(z(2,:));
        z3=mean(z(3,:));
        z4=mean(z(4,:));
        tem=1;
               
 %       z1=mean([imgn(i,j-1),imgn(i,j),imgn(i,j+1)]);
 %       z2=mean([imgn(i-1,j),imgn(i,j),imgn(i+1,j)]);
 %       z3=mean([imgn(i+1,j-1),imgn(i,j),imgn(i-1,j+1)]);
 %       z4=mean([imgn(i-1,j-1),imgn(i,j),imgn(i+1,j+1)]);

        imgn1(i,j)=max([z1,z2,z3,z4]);
    end
end
figure,imshow(imgn1,[]);