Patent ID: 7450771

Claim:
A method of optimizing compression of a still image in JPEG 2000 format, comprising the steps of: (a) dividing an image into a predetermined numbers of tiles each having a predetermined numbers of tile pixels; (b) decomposing each of said tiles into a predetermined number of subbands by Discrete Wavelet Transform (DWT); (c) partitioning each of said subbands into a predetermined number of code-blocks which are arranged into a plurality of bit-planes respectively; (d) optimizing a total rate with a given predetermined total distortion of the image so as to pre-determine an optimal truncation point for each of said code-blocks, wherein step (d) comprises: (d.1) determining a distortion and a rate of each potential truncation point of each of said code-blocks, (d.2) computing a slope value of each potential truncation point by said distortion and said rate of each potential truncation point, and (d.3) choosing a threshold for optimizing said total rate with a given total distortion; (e) truncating a predetermined part of said DWT coefficients for each of said code-blocks for minimizing computing resources; and (f) encoding each of said code-blocks by embedded block-coding to form an embedded code-stream having a plurality of coding passes.