I'd like to make an Android app that lets a user apply cool effects to photos taken with the camera. There are already a few out there, I know, but I'd like to try my own hand at one. I'm trying to figure out the best way to implement these effects. Here are some examples from the excellent Vignette app (which I own):
http://www.flickr.com/groups/vignetteforandroid/pool/
I have been googling and stack-overflowing, but so far I've mostly found some references to published papers or books. I am ordering this one from Amazon presently - Digital Image Processing: An Algorithmic Introduction using Java
After some reading, I think I have a basic understanding of manipulating the RGB values for all the pixels in the image. My main question is how do I come up with a transformation that produces cool effects?
By cool effects I mean some like those in the Vignette app or IPhone apps:
ToyCamera
Polarize
I already have quite a bit of experience with Java, and I've made my first app for android already. Any ideas? Thanks in advance.