Some Simple Parametric Lossless Image Compressors

This paper proposes lossless image compressors that are simpler than existing ones and yet still work well. The compressors process images in raster-scan order, and to code a pixel first estimate that pixel’s value by using a linear function of already-coded pixels. Next the compressors estimate the uncertainty in the first estimate by using a nonlinear function of already-coded pixels. Finally, based on these estimates, they select a discretized Laplacian with which an arithmetic coder represents the pixel. Alternatively, the compressors may select Golomb codewords based on the estimates, and thus directly represent the pixels. These compressors’ rates come within 6 to 8% of CALIC [1], a highlyeffective image compressor. Another benefit is that a simple theoretical motivation exists for the chosen uncertainty estimators.