Image compression using plane fitting with inter-block prediction

Abstract

This paper describes a simple scheme to compress images through plane fitting. The scheme can achieve better than 60:1 compression ratio, while maintaining acceptable image quality. The results are superior to those of JPEG at comparable compression ratios. The scheme does not require any multiplication or division operations, making it a perfect candidate for online and/or progressive compression. The scheme is scalable in the context of computations required to magnify the image. Blocking effects were reduced up to 0.85 dB of PSNR through simple line fitting on block boundaries. The performance of the scheme is further improved by optimizing its predicted model parameters based on previously coded neighbouring blocks. It is found that less than 2 bits (on average) are enough to index the position of the candidate neighbour, making a 100:1 compression ratio possible. The improvement in the compression ratio came at the expense of moderate to small quality degradations.