Entropy encoder for facsimile transmission

摘要

The encoder includes a reversible wavelet transform filter which transforms input data (101) into a number of coefficients representing decomposition of the input data. Decomposition can be performed using one-dimensional filters. A coder coupled to the reversible wavelet filter performs embedded coding of the coefficients so a bit stream is generated. Embedded coding (103) is performed using frequency-based modelling e.g. zero tree coding or joint spatial/frequency modelling e.g. horizon encoding to perform bit significance embedding. The bit stream is entropy-encoded (104) to create coded data (107). Coded data is generated prior to receiving all of the coefficient series.