You know those backgrounds that show cubes at different depths coming in and out of the screen...?
This wasn't what i was aiming for. it's neat but not exactly the result i was picturing.
I took an image of a cat's face, pixelized at 60 pixels x 60 pixels and gray scaled it to use as bump map.
Then took a light blue layer and bump mapped it hoping it could create the effect i am after which is cubes coming in and out of the screen. but nope ...

You could run the pixelized image through the Heightfield Offset by Values script to get something like this.

Ooooh... That's much more the effect i was going for.

If you could get that script to run on the channels then maybe it would come out in color.