Hierarchical Context-based Pixel Ordering

Abstract

We present a context-based scanning algorithm which reorders the input image using a hierarchical representationof the image. Our algorithm optimally orders (permutes) the leaves corresponding to the pixels, by minimizing thesum of distances between neighboring pixels. The reordering results in an improved autocorrelation betweennearby pixels which leads to a smoother image. This allows us, for the first time, to improve image compressionrates using context-based scans. The results presented in this paper greatly improve upon previous work in bothcompression rate and running time.Categories and Subject Descriptors (according to ACM CCS): I.3.5 [Computer Graphics]: Computational Geometryand Object Modeling I.3.6 [Computer Graphics]: Methodology and Techniques