A new color image compression algorithm based on DCT and hierarchical data structure

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 0.25bpp), with PSNR of about 32dB. For small distortion compressed image, we can obtain high PSNR of 49dB at 2.5dpp! The result is promising. Due to the hierarchical data structure, the encoded image can be transmitted progressively for practical Internet applications.