Dealing with the analysis, design, realization, implementation, and applications of digital filter in a straightforward and easy style, this text can serve either as a textbook on digital signal processing (DSP) with a strong emphasis on the design aspects of the discipline or as a state-of-the-art toolbox for researchers, engineers, and scientists. The analysis aspects include the study of finite-wordlength effects ranging from roundoff noise to limit-cycle oscillations. The design algorithms treated include both highly precise closed-form algorithms that yield standard filter types, e. g., elliptic recursive filters, as well as some very versatile iterative algorithms that can be used to design practically any type of recursive or non-recursive (IIR or FIR) filter. Among the iterative algorithms, a powerful quasi-Newton algorithm due to Fletcher and a very fast Remez algorithm are to be found. The realizations treated range from the well known standard direct and lattice realizations to the low-noise state-space and low-sensitivity wave realizations. The textbook also deals with several modern applications of digital filters, e. g., quadrature mirror-image channel banks and Hilbert transformers, and provides an introduction to two-dimensional and adaptive digital filters.