TO COMPUTER GRAPHICS BASED ONGKS Part I gives an introduction to basic concepts of computer graph ics and to the principles and concepts of GKS. The aims of this part are twofold: to provide the beginner with an overview of the terminology and concepts of computer graphics, based on GKS, and to give the computer graphics expert an introduc tion to the GKS standard. In the early chapters of this part, the main areas of computer graphics, the various classes of com puter graphics users, the interfaces of GKS and its underlying design concepts are discussed and important terms are defined. The later chapters give an informal introduction to the main concepts of GKS and their interrelationships: output, attributes, coordinate systems, transformations, input, segments, metafile, state lists, and error handling. This introduction to the GKS framework will prepare the ground for the detailed description of 2D GKS functions in Part III and the 3D extensions to GKS in Part IV. 1 WHAT IS COMPUTER GRAPHICS? 1. 1 Defmition of Computer Graphics The Data Processing Vocabulary of the International Organization for Stan dardization (ISO) ISO 84] defines Computer Graphics as follows: "Methods and techniques for converting data to and from a graphic display via computer. " This definition refers to three basic components of any computer graphics system - namely "data," "computer," and "display.""

This book is the sixth issue in the EurographicSeminars Series. This series has been set up by Eurographics, the European Association for Computer Graphics, in order to disseminate surveys and research results out of the field of Computer Graphics. Computer Graphics constitute a powerful and versatile tool for various application areas. The rapidly increasing use of Computer Graphics techniques and systems in many areas is caused by the availability of more powerful hardware at lower prices, ' by the concise specification of Computer Graphics Interfaces in commonly..agreed standards, and by the inven tion of new and often astonishing methods and algorithms for com position andpreserit ti6n of pictJres and for graphical interaction. While s, o e issues of this se.ries contain latest research results, e.g. the issues in window management systems or user interface manage ment systems, this book has the character of a state-of-the-art survey on important areas .of Computer Graphics. Starting from current practice and agreed consens, it will lead to the latest achievements in this field. The contributions in this issue are largely based on tutorials and seminars held at the Eurographics conferences 1984 in Copen hagen and 1985 in Nice."