Digital Color Management: Encoding Solutions, 2nd Edition

PART II

The Nature of Color Images

Color images are the end product of color-imaging systems. In digital imaging systems, however, color images are also a source of input. In fact, in many systems, color images—and not original-scene objects—are the principal source of the color information that will be encoded. It is important to recognize that most images used for input are produced on color-imaging media and by devices typically designed for entirely different purposes.

For example, reflection images, such as those made using inkjet, thermal, conventional photographic, or other technologies, are designed for direct viewing under typical room conditions. Reflective media thus have colorimetric reproduction characteristics optimized for that purpose.

Similarly, transparency media such as photographic slide films and motion picture print films can be used as input sources on digital imaging systems. Yet these media are specifically designed to produce images that are projected, using particular types of projection lamps, in darkened rooms or theaters. Because they are optimized for that purpose, these media have colorimetric color-reproduction characteristics quite different from those of other types of imaging media.

Photographic negative films are an important input source for certain professional digital imaging applications, especially motion picture. Although these media actually are well suited for digital applications, few are designed specifically for that purpose. Most ...