Division of entropy coding in codecs

摘要

There is described an image compressing/decompressing method and device that provides the lossless data compression/decompression scheme in two separate modules. Partially entropy encoded/decoded data is written to memory by a first module after a first part of the process and retrieved by a second module to perform the second part of the lossless compression/decompression scheme.

主权项

1. A method for compressing a data stream with a compression device comprising at least a first module and a second module, the method comprising:
processing the data stream using a lossy compression scheme to generate a set of reconstruction parameters and transform coefficients; reordering the transform coefficients in the first module; applying a first set of lossless encoding schemes to a first portion of the reconstruction parameters and the transform coefficients in the first module; selecting, in the first module, which ones of the reconstruction parameters and the transform coefficients will form part of a compressed bit stream and writing to memory selected ones of the reconstruction parameters and transform coefficients; retrieving from memory the selected ones of the reconstruction parameters and transform coefficients by the second module; applying a second set of lossless encoding schemes to a second portion of the reconstruction parameters and transform coefficients in the second module; and generating the compressed bit stream.