The intended audience for this book about digital color correction using Adobe’s Photoshop 3 is professionals working in the prepress image preparation stages, mainly at the cyan, magenta, yellow, key (CMYK) color separation level. The use of color correction curves is the main theme. The author’s goal in using color correction is to use all available positions in color space to create the biggest impact for an image. This view clearly conflicts with the color calibrationist view, which is aimed at providing reliable color transfer based on physical principles. I find the author too negative about device-independent color, since it can serve as a default for color correction when time or money is short.

The good thing about the book is that color correction is addressed in a global-to-local way. First, global changes like contrast maximization and redistribution of color values are applied using the color correction curves, and only when the results are still unsatisfactory are local and color-selective changes introduced.

The fact that the book is based on columns written for Computer Artist explains the narrative style of the text, which is full of hype words; a more formal style would have benefitted the book.

The examples provide insight into the sort of work prepress color correction deals with and how it can be done successfully. The book contains an introduction, 14 chapters, a glossary, and an index. The introduction confines the application to scanned photographic images and mainly deals with Photoshop image enhancement, features not well documented by Adobe.

In chapter 1, some insight is given into the fact that color depends on many variables. The CMYK separations are discussed, as are the tools needed from Photoshop. Chapter2 explains the many factors influencing color printing and how difficult it is to get a good idea of the final result. Chapter 3 is about graphics formats, such as TIFF, the Tagged Image File Format, and encapsulated PostScript.

In chapter 4, color correction curves are introduced as a powerful tool for global enhancement. Chapter 5 is mainly about ways to redistribute color values in such a way that no part of the actual color ranges remains empty. Global means having been discussed, chapter 6 introduces spatial selective and color selective changes whose effects, merged with the untreated parts of the image, are minimized by small-scale blurring around the silhouette edges.

Chapter 7 discusses retouching techniques and software sharpening of the image. The black channel (the K of CMYK color space) is the topic of chapter 8. Chapter 9 treats ways of using the least dominant color or unwanted color to enhance color contrast. In chapter 10, digital cameras and photo CDs are presented as ways to circumvent film and scanning altogether.

Making synthetic images by combining image elements from several pictures is the subject of chapter 11. Special applications, such as transforming a color image into a gray-level image and duotone printing, are discussed in chapters 12 and 13. Finally, chapter 14 introduces the new features of Photoshop 3: color density masks, the sponge tool, multiple layers, and synthetic lighting effects.

The glossary does not define all the terms used, and the definitions are often too imprecise to be of much use.

This book contains a lot of useful techniques, but part of it could have been replaced by material that gives more background. It lacks a chapter on the human visual system and the different ways to synthesize color in additive and subtractive color systems. Without this background, it is difficult to follow and evaluate suggested alternative approaches to color correction and enhanced perception.