Three-Dimensional Control of Color Management Systems - Control of Color Imaging Systems: Analysis and Design - page 302

7 Three-Dimensional

Control of Color
Management Systems

7.1 INTRODUCTION
A color management architecture for a digital imaging system provides a means for
processing digital images such that the colors produced on the output devices are a
reasonable representation of the colors in the input image

file may be
created using a computer or may be captured by other imaging devices such as a
scanner or a digital camera. The International Color Consortium (ICC) was set up to
provide a standard paradigm for managing color with image capture, display, and
rendering devices [1]. The algorithms described in this chapter use theoretical tools
from previous chapters to produce multidimensional color transforms for managing
color between devices. Numerous techniques for device characterization, gray com-
ponent replacement (GCR), and constrained inverse and gamut mapping are
described in detail. Some of these techniques use advanced control-based
approaches. A key output from this chapter is the well-tuned custom multidimen-
sional lookup table (LUT). These tables can be used to color-manage input images so
that when the resulting images are printed on output devices, they exhibit increased
color quality; better in terms of accuracy and consistency as compared to prints from
nonoptimal color management systems.

file. An image

7.2 IMAGE PATH ARCHITECTURE
The control of color is a system-wide problem. The color strategy followed by print
shops must use standards that provide a link between color transforms and numerous
devices so that the colors represented in different device-speci

c color spaces can
be transformed to a space local to the rendering device. The preferred industry
standard used by many production print shops for managing color is based on
standards set by the ICC. The ICC speci

cation is a vendor-neutral cross-platform
color management standard created by a group of industry color experts to improve
color work cation

divides color devices into three broad categories: input devices (e.g., RGB scanners,
RGB cameras, CDs, electronic documents), display devices (e.g., RGB monitors
and RGB projectors), and output devices (e.g., printers). For each device class, a

ow and is implemented in an ICC pro le format. The ICC speci

303