Patent ID: 7483575
Filing Date: 2009-01-27
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 encoding passes for encoding, as object of the encoding, for generating information on the number of the encoding passes, and counting a number of effective bitplanes, excluding zero bitplanes, for a total number of code blocks in a frame in an input picture, and reference is made to a predetermined table, based on the number of effective bitplanes, to find a number of bitplanes for encoding, from one frame to another; bit modeling means for performing bit modeling from one bitplane to another; encoding pass generating means for generating encoding passes from one bitplane to another; arithmetic coding means for performing arithmetic coding only on a number of the encoding passes, afforded by the information on the number of encoding passes, as counted from the most significant bit side of each code block, from among the encoding passes generated by said encoding pass generating means; code volume controlling means for controlling the code volume, based on an arithmetic code 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 code, controlled as to code volume by said code volume controlling means, to generate a packet.