Papers Published
- Weinberger, M. J. and Seroussi, G. and Sapiro, G., The LOCO-I lossless image compression algorithm: Principles and standardization into JPEG-LS,
IEEE TRANSACTIONS ON IMAGE PROCESSING, vol. 9 no. 8
(August, 2000),
pp. 1309--1324 [doi] .
(last updated on 2012/06/12)Abstract:
LOCO-I (LOw COmplexity LOssless COmpression for Images) is the algorithm at the core of the new ISO/ITU standard for lossless and near-lossless compression of continuous-tone images, JPEG-LS. It is conceived as a ``low complexity projection'' of the universal context modeling paradigm, matching its modeling unit to a simple coding unit. By combining simplicity with the compression potential of context models, the algorithm ``enjoys the best of both worlds,'' It is based on a simple fixed context model, which approaches the capability of the more complex universal techniques for capturing high-order dependencies. The model is tuned for efficient performance in conjunction with an extended family of Golomb-type codes, which are adaptively chosen, and an embedded alphabet extension for coding of low-entropy image regions. LOGO-I attains compression ratios similar or superior to those obtained with state-of-the-art schemes based on arithmetic coding, Moreover, it is within a few percentage points of the best available compression ratios, at a much lower complexity level. We discuss the principles underlying the design of LOGO-I, and its standardization into JPEG-LS.