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May 2003
701P40210
Xerox Document Services Platform
Color Management
Guide
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Xerox Corporation Global Knowledge and Language Services 800 Phillips Road Building 845-17S Webster, New York 14580 USA Copyright 2003 Copyright protection claimed includes all forms and matters of copyrighted material and information now allowed by statutory or judicial law hereinafter granted including without limitation, material generated from the software programs that are displayed on the screen such as styles, templates, icons, screen displays, looks, and so on. Printed in the U.S.A.,
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Table of contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 Multiple print engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 About this guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 Conventions . . . . . . . . . . . . . . . . . . . . . . .
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Table of contents Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 Tips for use of Xerox Qualified Stocks . . . . . . . . . . . . . . . . . . . . 3-3 Calibration process overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3 Calibrating the DocuColor 2045/2060/6060 family . . . . . . . . . . . 3-4 Calibrating the DocuColor iGen3 . . . . . . . . . . . . . . . . . . . . . . . . 3-4 Calibration target tips . . . . . .
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1. Introduction This guide is a reference to the DocuSP controller color management features. The DocuSP controller serves as the digital front end for preparing and processing jobs to print on Xerox color print engines. The DocuSP operator uses the information in this guide to enhance the use of the color management tools to achieve quality color output. Assumptions This guide assumes that the DocuSP operator is familiar with the DocuSP controller and the attached print engine, and is al
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Introduction Conventions This guide includes the following conventions: Angle brackets: Variable information that is displayed on your window or that can be entered as part of a command line is enclosed within angle brackets. Examples include "Unable to copy ;" “set –p .” Square brackets: Square brackets are used for the following: – Names of menu options that you select; for example, [Printer Default] – Names of buttons that you select; for example, [OK] and [Cancel
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Introduction Customer Support For service and software support, dial 1-800-821-2797. This number is enabled for TTY bridges. To reach Xerox Documentation and Software Services, dial 1-800-327-9753. Color Management Guide 1-3
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Introduction 1-4 Color Management Guide
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2. DocuSP color management Color management is a process of attempting to match colors across input (scanners, digital cameras), display (computer monitors), and output devices (color printers). Hardware devices such as Spectrophotometers for calibration and software tools such as color profiles, tone reproduction curves (TRCs) and color tools are used to match or adjust color to achieve a quality color image. Spectrophotometers are used to calibrate data for the print engine. Calibration
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DocuSP color management Color workflows A color image follows a path as it is converted from an input color profile to the output CMYK of the print engine. Factors that determine the path are: the characteristics and type of the input profile conversions needed for the output profile of the print engine enhancements made by you, the user Color path charts Jobs take one of five paths through the DocuSP controller. Whenever possible, you should use the Xerox Enhanced Path which provides
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DocuSP color management Figure 2-1. Simplified DocuSP Color Workflow ICC standard path Jobs undergo a color transformation to an independent color space before color transformation to the DocuSP print engine CMYK color space. This path requires more RIP time as the color is transformed from Input (such as RGB or input CMYK) to Profile Connection Space (PCS) to output CMYK or SWOP™ CMYK. The K channel will not be preserved for incoming CMYK data. The chief benefit of using this path is its
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DocuSP color management The incoming job contains embedded profiles that result in the printer driver creating a Color Space Array (CSA) for the color data. These PDL instructions are honored by the system. Xerox enhanced path Incoming RGB or CMYK data uses the DocuSP Xerox Enhanced Path Look Up Table (LUT) or Emulation LUT when performing the SWOP™ CMYK to DocuSP print engine CMYK transformation. Benefits of using this path include: Faster RIP time via use of the LUTs as contrasted wi
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DocuSP color management CMYK Native path Color management is performed within the application using DocuSP output color ICC profiles to create jobs composed with the DocuSP print engine CMYK color profile. These jobs are sent directly to the RIP with no color transformations, assuming you have not programmed any color adjustments. Documents destined for this path MUST be designed using the appropriate CMYK color space for the DocuSP destination print engine. This is usually achieved by usi
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DocuSP color management Color Manager Color Manager provides access to color management tools for calibration, characterization, assigning color profiles, managing color groups, creating and applying TRCs, and importing or exporting ICC profiles. Associations The Associations tab provides a list of stocks, their properties, date last calibrated, and the assigned profile. Calibration Calibration is used to return the print engine to a standard condition insuring color consistency for each st
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DocuSP color management NOTE: You should calibrate a stock that best represents the other stock in the group; therefore, you should calibrate using a stock that has a whitepoint at about the median of the stocks in the group. It is recommended that most users confine their use of color groups to the 3 pre-installed groups. This method provides excellent color results with relatively little user intervention. For a more in-depth discussion of color groups, see chapter 3: Calibration. Colo
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DocuSP color management Table 2-1. DocuColor iGen3 Digital Production Press mode default property settings Queue Property Queue Setting Rendering Intent Relative Colorimetric RGB Source sRGB CMYK Source SWOP™ CMY Source System Specified Gray Source Destination ICC Profile Front/ System Specified (pre-installed Back and optimized for the iGen3) Lightness 0 Contrast 0 Saturation 0 Color Cast (all) 0 TRCs None Press Color Emulation None Table 2-2. DocuColor 2045/2060/6060 mode default property s
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DocuSP color management Table 2-2. DocuColor 2045/2060/6060 mode default property settings Queue Property Queue Setting TRCs None Press Color Emulation None Xerox consistent color mode Selected at the queue level, Xerox consistent color mode standardizes the print engine response to undefined color spaces by assigning them default source files. Default Source files provide output that looks similar when submitted from the DocuSP to a compatible Xerox color print engine, currently the DocuC
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DocuSP color management Table 2-3. XCC mode default and override settings Queue Property Queue Setting Applicability Press Color None Override Emulation Custom color mode (default) Selected at the queue level, Custom Color mode allows users with a high level of color management skills to make specific color adjustments using industry standard color tools. Skilled users create queues with specific color properties, defaults and overrides. Jobs sent to these queues are assigned the queue prop
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DocuSP color management Black Overprint compensates for the band of white that may appear when black text is printed directly on top of a color. NOTE: Black Overprint produces sometimes-unexpected results using iGen3, due to its unique technology. Therefore, you should avoid using this feature on the iGen3. Anti-aliasing reduces the jagged appearance of lines and curves in text and line art. Expert color Expert color contains a set of tools for the skilled user to optimize color qualit
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DocuSP color management NOTE: These image resample methods are detailed in Chapter 4: Using Color Tools. – Output Destination Profiles convert PCS to CMYK. There are pre-defined destination profiles for GCR (Gray Component Replacement). GCR replaces equivalent percentages of the gray component for colors (CMY), replacing the gray with black. This conserves dry ink and prevents dry ink buildup. Emulation can be selected in place of destination profiles allowing you to select a color prof
