Optimal multifilter banks: design, related symmetric extension transform, and application to image compression

The design of optimal multifilter banks and optimum time-frequency resolution multiwavelets with different objective functions is discussed. The symmetric extension transform related to multifilter banks with symmetric properties is presented. It is shown that such a symmetric extension transform is nonexpensive. More optimal multifilter banks for image compression are constructed, and some of them are used in image compression. Experiments show that optimal multifilter banks have better performances in image compression than Daubechies' orthogonal wavelet filters and Daubechies' least asymmetric wavelet filters, and for some images, they even have better performances than the scalar (9,7)-tap biorthogonal wavelet filters. Experiments also show that the symmetric extension transform provided in this paper improves the rate-distortion performance compared with the periodic extension transform.