Low Pass Filter Use to Denoising

//Low Pass Filter Use to Denoising
>> orgImg=imread('cameraman.tif');
>> imgBinary=im2double(orgImg);
>> imgBinary=imnoise(imgBinary,'salt & pepper',0.05);
>> filter_1=ones(3,3)/9;
>> filter_2=ones(5,5)/25;
>> appFilter1=filter2(filter_1,imgBinary);
>> appFilter2=filter2(filter_1,imgBinary);
>> subplot(1,3,1), imshow(orgImg);
>> subplot(1,3,2),imshow(appFilter1);
>> subplot(1,3,3),imshow(appFilter2);