Non-photorealistic rendering

The ubiquity of computer-generated imagery around us, in movies, advertising or on the Internet is already being taken for granted and what impresses most people is the photorealistic quality of the images. Pictures, as we have often been told, are worth a thousand words and the information transported by an image can take many different forms. Many computer graphics researchers are exploring non-photorealistic rendering techniques as an alternative to realistic rendering. Defined by what it is not, non-photorealistic rendering brings art and science together, concentrating less on the process and more on the communication content of an image. Techniques that have long been used by artists can be applied to computer graphics to emphasize subtle attributes and to omit extraneous information. This book provides an overview of the published research on non-photorealistic rendering in order to categorize and distill the current research into a body of usable techniques. A summary of some of the algorithms as well as pseudo-code for producing some of the images is included.

• Preface p. xii
• 1 Introduction p. 1
• I Simulating Artistic Media p. 5
• 2 Simulating Artistic Media: Drawing p. 7
• 2.1 Background p. 7
• 2.2 Simulating Pencil p. 8
• 2.3 Simulating Pen-and-Ink p. 18
• 2.4 Summary p. 27
• 3 Simulating Artistic Media: Painting p. 29
• 3.1 Background p. 30
• 3.2 Simulating Brushes p. 31
• 3.3 Simulating Substrate p. 39
• 3.4 Simulating Media p. 45
• 3.5 Summary p. 49
• II Assisting a User in the Artistic Process p. 51
• 4 Assisting a User: Drawing and Painting Systems p. 53
• 4.1 Background p. 53
• 4.2 Artistic Rendering of Portrait Photographs p. 56
• 4.3 Paint By Numbers: Abstract Image Representations p. 63
• 4.4 Painterly Rendering for Animation p. 64
• 4.5 Digital Facial Engraving p. 67
• 4.6 Summary p. 71
• 5 Assisting a User: Modeling and Graftals p. 73
• 5.1 Sketching to Create Models p. 74
• 5.2 Graftals p. 85
• 6 Assisting a User: Animation and Three-Dimensional Environments p. 93
• 6.1 A Study of an Example NPR Animation p. 94
• 6.2 Two-Dimensional Systems p. 95
• 6.3 Three-Dimensional Systems p. 100
• III Automatic Systems p. 115
• 7 Feature Edges: Silhouettes, Boundaries, and Creases p. 117
• 7.1 Image Space Algorithms p. 120
• 7.2 Object Space Algorithms p. 129
• 7.3 Summary p. 145
• 8 Automatic Systems: Illustration p. 147
• 8.1 Artistic Line Drawing p. 147
• 8.2 Artistic Shading p. 160
• 9 Automatic Systems: Painting p. 189
• 9.1 Background p. 189
• 9.2 Processing Images and Video for An Impressionist Effect p. 191
• 9.3 Painterly Rendering with Curved Brushstrokes of Multiple Sizes p. 195
• 9.4 Statistical Techniques for the Automated Synthesis of Non-Photorealistic Images p. 207
• 9.5 Automatic Painterly Rendering Based on Local Source-Image Approximation p. 209
• 9.6 Artistically Motivated Halftoning p. 212
• 9.7 Summary p. 215
• Bibliography p. 219
• Index p. 241