Apple Inc.

Keith McGreggor

Ryoji Watanabe

Konstantin Othmer

James A Quarato

Robin D Myers

Jerry G Harris

David Van Brink

Robert G Johnson, Jr

Lindsay B Holt

Christopher M Yerga

A system for processing color information is based on carrying with color data, an indicator of the color space in which the data is represented. In this manner, the system is enabled to process color data from a variety of sources independent of the color space of the sources, because it is able to respond to the color space of a particular color value perform the necessary transformations to operate within any other arbitrary color and color space combination. The system provides for manipulating or combining colors independent of the source and destination color spaces. Also, the system operates on a per color component basis in user selected working color space, independent of the color space of the input or destination devices.

Color processing system

A color matching system initializes a translator by storing profiles of source and destination color devices which include the coordinates in a calibrated color space of the colorants produced in the source and destination devices and a tonal reproduction curve for each device. Mixing equations and parameters are precomputed to be used in matching calculations of an image including color pixels to be matched. The color gamut is divided into mixing regions in which a given point can be produced by a mixture of two chromatic colorants and the achromatic colorants of the destination device. A technique for selecting a mixing region is included which is based on the slopes of vectors defining the colorants of the destination device, and the sample color to be produced. Colors that are out of the gamut of the destination device are adjusted according to precomputed parameters in order to preserve the lightness, chromaticity, or other selected characteristics of the sample color as suits the need of a particular application. The system is particularly suited for computer systems independent of the source and destination devices to be used, and can be adapted to run with a translation cache to enhance the speed of operation of translating a color image on one device for display on a second device.

Color matching apparatus and method

An operating system software architecture, implemented in an object-oriented design, supports and processes color. The object-oriented design has two levels, one being a class (TColor) defining a virtual abstract base class and being a container class containing calibrated colors, the other being a class (TDeviceColor) defining a virtual abstract base class and a container class containing uncalibrated colors. Several calibrated color classes including a class (TXYZColor) defining XYZ color space descend directly from class (TColor), several uncalibrated color classes including a class (TRGBColor) descending directly from class (TDeviceColor), a class (TColorGamut) storing color gamut information of peripheral devices that may interface with the architecture, and a class (TColorProfile) storing tonal reproduction curves of the peripheral devices provide data structures, together with method functions for various color processing. The architecture is extensible to add new color classes as new color models and devices are developed, to add new color matching algorithms as desired, allows users to work in color space of their choice, and provides for color matching amongst any peripheral devices interfacing with the architecture.

Operating system software architecture and methods for supporting color

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San Jose, CA, United States of America

Keith McGreggor