Two-Dimensional Delta-Mod Facsimile Coding

A new facsimile source coding algorithm, called twodimensional (2-D) delta-mod (Δmod), is presented. The algorithm is based on conventional run length coding. Additional compression is achieved by vertically delta-modulating the horizontal run lengths. The delta-modulation introduces a distortion into the image which can be traded-off versus the rate of transmission. Cumulative error is prevented, as in conventional Δ mod, by including the (run length) quantizer in the feedback loop. Some parametric results are presented