Comparison of directionally based and nondirectionally based subband image coders
Roberto H. Bamberger, Mark J. T. Smith · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1991
Many different types of analysis/synthesis decompositions have been investigated for image coding. Some, like those used in traditional transform, pyramid, and subband coders, partition the spatial-frequency spectrum into symmetric bands, i.e., the bands occupy a disjoint region in each of the four frequency plane quadrants [1, 2, 3, 4]. Others have examined related systems that use directionally-based decompositions [5, 6, 7, 8] in which diagonally oriented spatial frequency components are coded. However, the directional resolution in these schemes is often very limited. In this paper, some new exactly reconstructing subband decompositions are presented with directional selectivity. They are examined in the context of subband image coding and compared to directionally invariant subband decompositions in terms of subjective quality.