Quadrature-mirror-filter design for the subband coding of digital video signals

The paper firstly reviews the basic two-channel subband coding system and its implementation using both quadrature mirror filter (QMF) and conjugate quadrature filter (CQF) designs. Their features and performance characteristics for the one-dimensional case are examined and then using the principle of separability, 2-D QMF-CQF implementations are constructed, as the product of two l-D transfer functions. Examples of 2-D QMF-CQFs in band-splitting configurations for video applications are explored and discussed.