Signal processing plays a large part in our everyday lives and will continue to do so in the future. This book summarizes the results of researches conducted by the authors and their students for the development of methods, algorithms, and software for digital processing and recovery of signals. A new method is described for the issue of modeling one-dimensional and multidimensional signals as succession of local polynomial splines and their spectral characteristics. Some signal processing examples are implemented in MATLAB environment and models of special processes in Simulink environment are also described. Several features of this book not only makes it unique but makes it easier for beginners to understand the basic concepts of polynomial splines. Throughout the book, we have tried to emphasize the concept of mathematical model and their application oriented simulation results. We believe an understanding of the concept leads to an understanding of the computing structure. The book is intended for engineers, undergraduates, postgraduates, doctorate and scientific degree applicants who carry out research, evaluation, and designing of hardware and software for DSP and Systems.