Maximization of Coding Gain of Orthogonal and Linear-phase Subband Filters
Masayuki Tanimoto, Hiroki Minami, Tadahiko Kimoto · International Symposium on Information Theory and its Applications · 1994
In the sub-band coding dividing the picture signal into two channels, orthogonal and linear-phase analysis/synthesis filters with the number of taps L more than 2 are trivial since the coding gain of such filters is small. In this paper, we derive the general expressions of orthogonal and Linear-phase sub-band filters for L = 2N and L = 4N in the case N > 2, where N denotes the number of channels. Then, based on these expressions, the orthogonal and linear-phase sub-band filters with maximal coding gain are derived for picture signals expressed by the AR model. The derived filters of L = 2N achieve coding gain larger than that of the LOT that is known as a filter of L = 2N with high coding gain. Further improvement of coding gain is achieved by the filters of L = 4N compared to that of L = 2N.