Low bit rate subband DCT image compression

This paper describes two novel methods to improve the efficiency of the subband coding by means of the energy compactness in the frequency domain. Our coding scheme employs a variable block size DCT to the subband signal to get high coding efficiency. A class driven segmentation is devised here as a variable block partition scheme. Besides, an information oriented coding strategy without side information is developed here. The strategy not only retain the image properties but also reduce the computation overhead. Simulations are carried out to the Lena image, and their results show the effectiveness of the two approaches especially for low bit rate applications.