The most outstanding feature of this book is that it treats the design of filters that approximate a constant group delay, and both, the prescribed magnitude and group delay response of one-dimensional as well as two-dimensional digital filters. It so fills a void in the literature, that almost solely deals with the magnitude response of the filter transfer function. The volume contains many of the important results that have appeared in professional journals only recently. Contents: - Classical Methods of Approximation. - Magnitude and Delay of 1-D Digital Filters. - Magnitude of 2-D Digital Filters. - Magnitude and Delay of 2-D Digital Filters.