What is a color image?, What is a color table?

Appendix A Color Concepts

What is a color image?

A digital color image contains information about a scanned document subdivided into many small regions called pixels (picture elements). Each pixel is represented as a 24-bit value. These 24 bits are used to indicate the amount of red, green and blue for each pixel. Pixels are arranged in a matrix to collectively represent the image. Each pixel represents a single color, present at that location in the image.

What is a color table?

What is the Brightness and Contrast Control?

The color cameras in a scanner typically deliver three channels of data to the image processing system, representing the Red, Green, and Blue content of the image.

This raw data can then be fine-tuned to more closely represent the original document by mapping raw input colors to the desired output colors. This is usually done with a color table. The color table is simply a list of input values matched to the desired output colors.

The purpose of the Brightness and Contrast Control is to provide a tool whereby a user can adapt or develop a custom color table for a Kodak Innovation Series Scanner, to suit the needs of a particular application. The Brightness and Contrast Control provides a graphical user interface which allows the user to preview the effect a color table will have on a representative customer image. It can acquire a representative image from the Kodak Innovation Series Scanner or load it from a file. The utility provides tools which permit creating, modifying and saving custom color tables.

24	A-61506 September 2006