Directional interpolation pyramids for still image compression

Reduced pyramids, i.e. pyramids without analysis filters are known to produce excellent results when used for lossless signal and image compression. The paper introduces a novel method for the construction of reduced pyramids with synthesis filters adapted to the orientation of local image features. It is shown that this construction produces more accurate interpolation than conventional reduced pyramids. It also has the added advantage of producing lossy replicas of the original, which, at lower resolutions lack undesirable artifacts near edges. Experimental evaluation shows that the resulting method produces results comparable and often superior to those of the most efficient known algorithms for progressive lossless image coding.