The analysis and design of two-dimensional nearly-orthogonal symmetric wavelet filter

The analysis and design of two-dimensional nearly-orthogonal symmetric wavelet filter has been studied. Methods for analyzing the correlation of the nearly-orthogonal filter banks are proposed. The basic idea is to impose multiple zeros at the aliasing frequency to a symmetric filter, minimize the deviation of the filter satisfying the orthogonal condition, then a nearly orthogonal filter bank can be obtained. The way in this paper is to find a FIR complementary filter of the minimized filter and thus construct a perfect reconstructed biorthogonal filter bank. Then a corresponding wavelet filter bank can be generated and correlation analysis can also be conducted.