3-D subband video coding technique using adaptive wavelet packet bases

In this paper, we propose an adaptive 3-D subband video coding technique based on the rate-distortion optimal wavelet packet bases. The input image sequence is first transformed by DCT in temporal domain and the lowest temporal frequency frame is split into fine uniform subbands by considering correlation and energy in the frame. Other higher frequency frames show various energy distributions, with respect to the motion in the image sequence. Thus, adaptive 2-D wavelet packet bases, which are optimal in rate-distortion sense, are applied to these high frequency frames. We also propose a coding gain optimized CQF(Conjugate Quadrature Filter) design technique, assuming AR(1) input source model, and apply it to the 3-D subband coding technique. Moreover, we investigate the adaptivity of temporal domain transform by the performance comparisons of the 4-tap and 8-tap DCT. From the simulation results, the proposed 3-D subband coder shows a better performance than the fixed wavelet packet bases scheme. And it is shown that the adaptive temporal transform can considerably improve the 3-D subband coder performance