!怎么加入对高斯噪声和椒盐噪声的加权均值滤波（分别用[3 3]和[5 5]尺寸）

I=imread('electric.tif');
a= imnoise(I,'gauss',0.02); %添加高斯噪声
b = imnoise(I,'salt & pepper',0.02); %添加椒盐噪声
ave1=fspecial('average',3); %产生3×3的均值模版
ave2=fspecial('average',5); %产生5×5的均值模版
a1 = filter2(ave1,a)/255; %均值滤波3×3
a2= filter2(ave2,a)/255; %均值滤波5×5
b1 = filter2(ave1,b)/255; %均值滤波3×3
b2= filter2(ave2,b)/255; %均值滤波5×5
a3 = medfilt2(a,[3 3]); %中值滤波3×3模板
a4= medfilt2(a,[5 5]); %中值滤波5×5模板
b3 = medfilt2(b,[3 3]); %中值滤波3×3模板
b4= medfilt2(b,[5 5]); %中值滤波5×5模板
imshow(I);
figure,imshow(a);
figure,imshow(b);
figure,imshow(a1);
figure,imshow(a2);
figure,imshow(a3);
figure,imshow(a4);
figure,imshow(b1);
figure,imshow(b2);
figure,imshow(b3);
figure,imshow(b4);