SPLITTING A MATRIX OF LAURENT POLYNOMIALS WITH SYMMETRY AND ITS APPLICATION TO SYMMETRIC FRAMELET FILTER BANKS.

Let M be a 2 × 2 matrix of Laurent polynomials with real coefficients and symmetry. In this paper, we obtain a necessary and sufficient condition for the existence of four Laurent polynomials (or finite-impulse-response filters) u1, u2, v1, v2 with real coefficients and symmetry such that [This symbol cannot be presented in ASCII format] and [Su1](z)[Sv2](z) = [Su2](z)[Sv1](z), where [Sp](z) = p(z)/p(1/z) for a nonzero Laurent polynomial p. Our criterion can be easily checked and a step-by-step algorithm will be given to construct the symmetric filters u1, u2, v1, v2. As an application of this result to symmetric framelet filter banks, we present a necessary and sufficient condition for the construction of a symmetric multiresolution analysis tight wavelet frame with two compactly supported generators derived from a given symmetric refinable function. Once such a necessary and sufficient condition is satisfied, an algorithm will be used to construct a symmetric framelet filter bank with two high-pass filters which is of interest in applications such as signal denoising and image processing. As an illustration of our results and algorithms in this paper, we give several examples of symmetric framelet filter banks with two highpass filters which have good vanishing moments and are derived from various symmetric low-pass filters including some B-spline filters. [ABSTRACT FROM AUTHOR]