Xerox 560 L*a*b, long-edgefirst LEF, lookup table LUT, Pdf/X, PPD PostScript Printer Description

148 Chapter 15—Glossary

L*a*b*

A device-independent color measurement system that measures Lightness (or Luminance) and two color coordinates, A (red/green) and B (blue/yellow). It may be used as an intermediate color space used when converting from one color space to another (for example, from CMYK to RGB).

long-edge first (LEF)

A printer page orientation where pages are delivered to the printer with the long edge of the paper going in first.

lookup table (LUT)

A two or three-dimensional array of values that stores information about specified input-output relationships. When an input value is known, the system can automatically determine the correct output value. For example, the system can find the required dot size for a given set of printing conditions based on the stored gray level.

Color setups can be saved in color tables (color transformation tables), which is one of the many kinds of LUTs.

PDF/X

Abbreviation for Portable Document Format eXchange. An exchange format for sending pages between a page preparation site and a printing site. PDF/X is a subset of the full PDF specification.

PPD (PostScript Printer Description)

A file specification set by Adobe Systems, Inc. It contains output- device-specific information, including fonts, line screens, offset margins, supported page sizes, and so on.

pre-separated file

A PDF, PostScript, or TIFF file that contains a separate page for each color in a document. A standard process color job would have four pages—one for each process color. A job with spot colors would have a page for each spot color and a page for each process color.