A time-effective lossless coder based on hierarchical contexts and adaptive predictors

In the paper an efficient and time-effective lossless coding technique is presented. The method is context-based, three principal contexts are defined, for neighborhoods with special properties three auxiliary contexts are used. A simple predictor adaptation technique, being extension of ALCM algorithm, is implemented, hence, it is proposed to denote the new method as ALCM+. A sophisticated formula for correcting the cumulated predictor error combining 8 bias estimators is calculated. Performance of the new algorithm has been tested on the set of 9 widely used benchmark images. It has been shown that indeed, the new technique has been time-effective while it has outperformed the well known methods having reasonable time complexity, like CALIC, or JPEG-LS, and has been inferior only to those that are extremely computationally complex.