New color image compression algorithm based on DCT and hierarchical data structure
Alan Ng, Bing Zeng · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1998
Nowadays, since the bandwidth is very expensive in most cases of the real-world telecommunications, we need to compress the amount of image data being transmitted. The main drawback for lossy compression is that we cannot completely restore the original images. We have to make a compromise between bit-rate and distortion. In the paper, we propose a new scalable image compression algorithm using (1) Quad Tree data structure, (2) DCT and (3) Hierarchical DPCM encoding. For high compression, we are able to achieve compression factor of 48 (at 0.25 bpp), with PSNR of about 32 dB. For small distortion compressed image, we can obtain high PNSR of 49 dB at 2.5 dpp result is promising. Due to the hierarchial data structure, the encoded image can be transmitted progressively for practical Internet applications.