ArtRage Studio Pro has two built-in image processing effects, and also supports many industry-standard plugin image filter effects.
The built-in effects:
Blur: applies a Gaussian blur to the layer
Colour Adjust: Tweak the Brightness, Contrast, Hue, Colour richness of the layer (either as paint colour before lighting is applied, or as a flat layer bitmap)
These two we felt were the two most important 'work-horse' effects for digital art, so deserved to be integraded fully into ArtRage. It also meant that we laid the groundwork for adding other built-in image processing effects in future updates.
More information will be forthcoming soon.
AndyRage's mantra for graphics engine code:
"Sure - how hard can it be?"