2-dimensional recursive orthogonal wavelet transformation
H. Yasuoka, Masaaki Ikehara · 2002
The design of a 2-dimensional (2-D) recursive orthogonal wavelet based on iterated filter banks is investigated. To obtain the orthogonal wavelet, we use the parallel connection of some delays and a 2-D allpass filter. In this case, a pair of digital filters with orthogonality is obtained structurally and digital filters with arbitrarily orders can be designed. Furthermore a maximum number of zeros is put at aliasing frequencies in the lowpass filter to obtain the regularity of the wavelet. Design examples of discrete scaling and wavelet functions are presented.>