New results on multidimensional filter banks and wavelets
New results on multidimensional filter banks and wavelets are presented. Emphasis is placed on the two-dimensional case with sampling by 2 in each dimension. It is shown how, by using an appropriate cascade structure, nonseparable filters being both orthogonal and linear phase can be obtained, a construction not possible when one-dimensional systems are used separately. The condition for having at least one zero of the lowpass filter at all aliasing frequencies (necessary for convergence) is given. A first design example of two-dimensional orthonormal wavelets with symmetries is presented, together with a demonstration of continuity.<<ETX>>