Patent ID: 7925102
Filing Date: 2011-04-12
Classification: G06T

Abstract:
1. An image encoding apparatus, comprising: filtering means for generating a plurality of sub-bands, and applying hierarchical filtering to the sub-bands; code block generating means for splitting the sub-bands generated by said filtering means for generating a plurality of code blocks each being of a predetermined size; bitplane generating means for generating a plurality of bitplanes from the most significant bit to the least significant bit, in terms of said code block as a unit; encoding object predicting means for predicting a number of bitplanes for encoding, as object of the encoding, and for extracting, from an upper bit side of each code block, only a number of bitplanes corresponding to a predicted number of bitplanes for encoding, and counting the number of the effective bitplanes, excluding zero bitplanes, for the totality of the code blocks in the sub-bands of an input picture, and wherein reference is made to a predetermined table, based on the count results, to find the number of the bitplanes for encoding, from one sub-band to another; bit modeling means for performing bit modeling from one bitplane extracted by said encoding object predicting means to another; encoding pass generating means for generating an encoding pass from one bitplane to another; arithmetic coding means for performing arithmetic coding in the encoding passes generated by said encoding pass generating means; code volume controlling means for controlling the code volume, based on arithmetic codes generated by said arithmetic coding means, so that a target code volume will be reached; and packet generating means for appending a header to the arithmetic codes controlled as to code volume by said code volume controlling means, to generate a packet.