Efficient processing of JPEG2000 imagery

Although optimal truncation of JPEG2000 compressed imagery provides an image of the highest quality per bitrate in terms of PSNR, the algorithm is highly computationally inefficient because of the removal of compressed image sections that have been previously calculated. The proposed idea utilizes a simple quantization technique prior to Tier I coding to remove many of the coding passes from the imagery that would not become a part of the final compressed bitstream. A new method based on the this idea is discussed. The method restricts the quantization value to be a power of 2, effectively eliminating the least significant bits of each codeblock through the quantization step, providing substantial reduction in computational complexity, a 39% reduction in overall complexity at 0.25 bits per pixel. The new method gives an equivalent rate distortion curve as traditional optimal truncation.