A novel morphological subband decomposition scheme for 2D+t wavelet video coding

Interframe or 2D+t wavelet video coding leads to a scalable video coding framework with all three scalabilities: quality (PSNR), spatial and temporal. One of the major challenges in the 2D+t frame work is the spatial (2D) decomposition of detail frames produced by the temporal decomposition process (t). Detail frames are different from still images so that better coding performance can be achieved by using nonlinear spatial decomposition techniques. In this paper, a wavelet transform based on a novel morphological operator, the complete inf-semilattice (or cist-) erosion, is presented and its coding performances for detail frames are compared with the existing nonlinear transforms based on the median operator and linear wavelet transforms used in still image coding. The simulation results show that the cisl-erosion based wavelet decomposition outperforms the median based wavelet decomposition for all temporal subbands and performs better or comparably with the 5/3 biorthogonal wavelet transform in most cases.