Multi-Scale Probabilistic Dithering for Suppressing Banding Artifacts in Digital Images

A method is proposed for reducing the visibility of "banding artifacts," i.e. false contours resulting from color quantization in digital images. The method performs a multi-scale analysis on the neighborhood of each pixel, determines the presence and scale of banding artifacts, and probabilistically dithers (perturbs) the color of the pixel. The overall effect is to "break down" the false contours making them less visible. The proposed method may be used to reduce banding artifacts at the same bit depth as the input image or at higher bit depths. The banding detection mechanism ensures that artifact-free regions remain unaffected during the process.