Patent ID: 7454354

Claim:
A hierarchical lossless encoding and decoding method comprising the steps of: in an encoding apparatus, encoding an input signal into low-bit-rate encoded data and transmitting the low-bit-rate encoded data to a decoding apparatus; encoding a differential signal between a low-bit-rate decoded signal produced by decoding said low-bit-rate encoded data and said input signal, into lossless encoded data, and transmitting the lossless encoded data to the decoding apparatus; and extracting corrective information from said low-bit-rate decoded signal and transmitting the corrective information to the decoding apparatus; in the decoding apparatus, decoding the low-bit-rate encoded data transmitted from the encoding apparatus into a low-bit-rate decoded signal; decoding the lossless encoded data transmitted from the encoding apparatus into a differential signal; and correcting said low-bit-rate decoded signal based on the corrective information transmitted from said encoding apparatus, and adding the corrected low-bit-rate decoded signal and said differential signal into a lossless reproduced signal.