Quadtree based JBIG compression

A JBIG compliant, quadtree based, lossless image compression algorithm is described. In terms of the number of arithmetic coding operations required to code an image, this algorithm is significantly faster than previous JBIG algorithm variations. Based on this criterion, our algorithm achieves an average speed increase of more than 9 times with only a 5% decrease in compression when tested on the eight CCITT bi-level test images and compared against the basic non-progressive JBIG algorithm. The fastest JBIG variation that we know of, using “PRES” resolution reduction and progressive buildup, achieved an average speed increase of less than 6 times with a 7% decrease in compression, under the same conditions