Compaction of ordered dithered images with arithmetic coding.

Ordered dither is considered to be a simple and effective method among all halftoning techniques. In this paper, compaction of ordered dithered images using arithmetic coding is studied. A preprocessor referred to as pixel interleaving (i.e., grouping pixels with similar dithering thresholds) is employed in such a way that dithered images can be efficiently coded with the JBIG1 code and high compressibility can be achieved. Experimental results reveal that the four-pixel interleaving achieves the best compression performance.