Image Compression Using Vector Coding Techniques. Final Report, July 15-September 30, 1981

摘要

Software for cluster design of codebooks for image block (or vector) coding has been developed and successfully tested. Preliminary results used a data base consisting of one 1024 by 1024 pixel image called LAX, stored at 8 bits per pixel. The cluster design algorithm was used to obtain a codebook of 64 representative 2 by 2 image blocks by training on 16,000 blocks from a 256 by 256 sector of the LAX image. The same 256 by 256 segment of the LAX image was compressed from 8 bits per pixel to 1.5 bits per pixel using this codebook. The reconstructed image was of remarkably good quality considering the low dimensionality of the block size chosen. Some degree of edge degradation was observed, but the overall quality far exceeded our expectations for our first attempt at vector image coding. Photos in the original copy of this report illustrate the results. These results are likely the first ever obtained using vector coding for image processing. The conclusion based on this preliminary study is that vector coding is indeed a very promising technique for image coding. (ERA citation 07:006611)