Dinei Florencio and Patrice Simard
Many image coders map the input image to a transform domain, and encode
coefficients in that domain. Usually, encoders use previously transmitted
samples to help estimate the probabilities for the next sample to be encoded.
This backward probability estimation provides a better PDF estimation, without
need to send any side information. In this paper we propose a new method
of encoding that goes one step further: besides past samples, it also uses information
about the current sample in computing the PDF for the current
sample. Yet, no side information is transmitted. The initial PDF estimate is
based on a Tarp filter, but probabilities are then progressively refined for nonzero
samples. Results are superior to JPEG2000, and to bit-plane Tarp.