Boundary Issues

Method 1: clip filter - assmue the out of boundary is black

imfilter(f,g,0)

Method 2: warp around - the image wraps around the outside (periodic signal)

imfilter(f,g,’circular’)

Method 3: copy edge(replicate) - extend the edge to outside (easy and reasonale)

imfilter(f,g,’replicate’)

Method 4: reflect across edge(symmetric) - reflect the image to the outside.

imfilter(f,g,’symmetric’)