I was using the "Poster Edges" filter in Photoshop on a recent project and liked the effect. Thought I'd try a few UW images. Best shots are bright and graphic. Harder-edged critters like crabs work nicely. You can control width, intensity and number of colors used in the posterization. Easy to set up and use. I have some more on my Flickr site.
Blue Spotted Sting ray
Brown Xeno Crab
And my favorite:
Puget Sound King Crab C.U.
Jack
Neat effect. I really like the Xeno Crab. It looks like a comic book character.
Jack,
Can you post before pics too? That'd be a neat comparison.