Chroma keying and alpha matting

Some tools I developed to optimize my workflow and improve the quality of my compositing projects.

Bayesian matting

I Implemented an improved version of the Bayesian matting algorithm shortly after the original paper was published. Initially it was a command line tool and later a plugin for the Ramen compositor and a Spark for IFFS systems.

The tool required a trimap (3 level alpha channel) that classifies pixels as foreground, background or unknown and estimated the foreground and background colors and opacity of the unknown pixels using Bayesian statistics. Optionally, a clean background plate could be provided to improve the estimation.

I used the tool frequently in production. It produced excellent results for complex chroma keying jobs (hair, motion blur, transparent objects, ...).

I'm currently working on an updated version of this tool.

Image segmentation

I wrote a graph cut image segmentation tool as a plugin node for the Ramen compositor. I used it as a first step to generate quick masks for color corrections and trimaps for Bayesian matting.