This book provides an accessible introduction to signals and systems by beginning with an early introduction to cound and image applications, as opposed to circuits, that motivate readers to learn the theory. The book is accompanied by a robust website with detailed notes and illustrative applets for most every topic. An accessible introduction to the topic that assumes no background in circuits. Starts by presenting applications, which successfully motivates students learn the theory. An appropriate presentation for computer engineers and computer scientists students. Includes extensive web material for students and instructors with dynamic, illustrative applets for most topics. Incorporates lab material that ties the theory of the text into real-world applications of signals and systems. Based on many years of successful class-testing at the authors' university. This book is designed for students taking an introductory signals and systems course, as well as engineers looking for a fresh coverage of this important topic.