A unified and coherent introduction to the notion of abstraction in interactive computer graphics is provided by this book. Abstraction entails refinement of images based on geometric models so as to reflect the importance of the features of the model for the dialog context and the visualization goal. This may require leaving out irrelevant details or accentuating significant features by adding details or enlarging or deforming parts. Such modifications are routine by hand but are at the leading edge of research in 2D and 3D computer graphics. The authors see the abstraction process as an interactive exploration of complex information spaces, and report especially on zooming and rendering techniques. Benefits are discussed for applications in medical illustration and technical documentation.