I need an edge dilation filter (GLSL)!!!

People,

I have a trouble. I have an image, and a shadowmap of this image done. Trough the shadowmap and applying a sobel edge filter i could find the contours of the shadowmap. Now my purpose is to dilate them. Unfortunately i could not find any example of this here except this one made by PocketMoon:

http://www.opengl.org/discussion_boards/ubbthreads.php?ubb=showflat&Number=223976

Unfortunately i don’t have acess to this file, and i can’t seem to find any similar example in the internet! Can anyone help me? Here’s my project. What do i have to code/do? http://rapidshare.com/files/265864726/Shadow_Mapping_with_GLSL.zip.html

dilation filter is very basic, just take the max intensity (or min, if your edges are black) from your samples.