Low bit-rate image coding based on pyramidal directional filter banks

This paper presents a novel embedded image coding system based on the pyramidal multidirectional image representation. The multiscale filter bank is a combination of the overcomplete pyramidal directional filter bank at higher scales and the traditional maximally-decimated wavelet filter bank at lower scales, to provide a sparse image representation. The coding algorithm then efficiently clusters the significant coefficients using progressive morphological operations. Context models for arithmetic coding are designed to exploit the intra-band dependency and the correlation existing among the neighboring directional subbands. Experimental results show that the proposed coding algorithm outperforms the current state-of-the-art wavelet based coders, such as JPEG2000, for images with directional features.