New Color Spaces

• CMYK color model and support for color images. Enhanced functionality. This will encourage more ISVs to use the color operators, because the operators will be widely available (The printer itself may not be able to print in color, but the PostScript language program won't generate errors when the operators for CMYK color are used.)
• PostScript Level 2 supports several device-independent color spaces based on the CIE 1931 (XYZ)-space. CIE-based color specification enables a page description to specify color in a way that is related to human visual perception. The goal of the CIE standard is that a given CIE-based color specification should produce consistent results on different color output devices, independent of variations in marking technology, ink colorants, or screen phosphors. True device-independent color specification. Improved color matching between devices.
• PostScript Level 2 supports three classes of color spaces: device independent, special, and device dependent.

The following device independent color spaces are standard:

The CIEBasedABC color space is defined in terms of a two-stage, non- linear transformation of the CIE 1931 (XYZ)-space. The formulation of the CIEBasedABC color space models a simple zone theory of color vision, consisting of a non-linear trichromatic first stage combined with a non-linear opponent color second stage. This formulation allows colors to be digitized with minimum loss of fidelity; this is important in sample images.

Special cases of CIEBasedABC include a variety of interesting and useful color spaces, such as the CIE 1931 (XYZ)-space, a class of calibrated RGB spaces, a class of opponent color spaces such as the CIE 1976 (L*a*b*)-space and the NTSC, SECAM, and PAL television spaces.

The CIEBased A color space is a one-dimensional and usually achromatic analog of CIEBasedABC.

The following special color spaces are standard:

• The Pattern color space enables painting with a ``color'' defined as a pattern, a graphical figure used repeatedly to cover the areas that are to be painted. See the discussion of patterns for more information.
• The Indexed color space provides a way to map from small integers to arbitrary colors in a different color space such as a device independent color space.
• The Separation color space provides control over either the production of a color separation or the application of a device colorant, depending on the nature and configuration of the device.

The following device dependent color spaces are standard:

• The DeviceGray color space is equivalent to the existing PostScript language's gray color model.
• The DeviceRGB color space is equivalent to the existing PostScript language's red-green-blue (RGB) color model.
• The DeviceCMYK color space is equivalent to the existing PostScript language's cyan-magenta-yellow-black (CMYK) color model.