For your first step select one existing image or create your design as you like.
First, right click on the image and select Filters -> Edge-Detect-> Difference of Gaussians
from the menu. Apply the filter, and watch what happens to the image. It is used for edge
detection with control of edge thickness.
And also add one more effect: Filters -> Light and Shadow -> Xach Effect.
(Add a subtle translucent 3D Effect to the selected region or alpha ) then they display
shadow and highlight layer masks.
Now we have enhancing edges then one more effect : Filters -> Artistic
->Cartoon, after we select : Filters -> Artistic-> softglow, Now that there is a soft edge.
Our last step, Now we want to see difference in filmstrip combine images then one more effect :
Filters -> Combine-> Filmstrip.