Did you ever wish you had a set of specialized blur, sharpen, or edge detect filters? Have you ever wanted an emboss filter that retains the colors of your original image? Maybe you yearned for a filter that would give you something kinda funky. If so, you should probably take a look at User Defined Filters.
User Defined Filters (UDFs).
In our first UDF tutorial we looked at the basic rules of thumb for making UDFs, and we made a couple blur filters. In the second UDF tutorial, we made some sharpen filters. In this tutorial, we'll make a couple edge detecting filters.