how to use function colfilt?

I want to filter an image by using non linear spatial filters. I used the command colfilt(I,[3 3],'sliding',fun 'parameter'); I am confused what does parameter mean here. i used w=fspecial('laplacian',0) to replace the parameter by w. but it still doesn't work. any help?

Answer 1

[Image Analyst]

I don't know - it's just unnecessarily complicated so I never use it. I don't think it's needed. Whatever it does, it doesn't do anything that's not done easier with simple to understand functions like conv2, imfilter, nlfilter, or blockproc.