Dye Sublimation Color Management
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Dye Sublimation Color Management Achieving Accurate Color Output Using Standardized Processes
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Achieving Accurate Color Output Using Standardized Processes. Dye Sublimation Color Management. Color Gamut. Definition of GAMUT The subset of colors which can be accurately represented within a given color space or by an certain output device and ink combination. - PowerPoint PPT Presentation
Transcript of Dye Sublimation Color Management
Dye Sublimation Color ManagementAchieving Accurate Color Output Using Standardized Processes
Color Gamut
Definition of GAMUT
1. The subset of colors which can be accurately represented within a given color space or by an certain output device and ink combination.
2. The complete set of colors found within an image at a given time. Converting a digitized image to a different color space, or printing it to a given medium generally alters its gamut.
The gray area represents the entire chromatic range. The colored triangle represents the color display. This is a typical CRT gamut reflected by the sRGB ICC profile.
RGB and CMYK
RGB. Three colors of light, red, green and blue make white light. Cyan, magenta and yellow are also combinations of RGB.
The intensity of light also changes the color.
CMYK. Three inks, cyan, magenta and yellow make black. In practice this black lacks intensity, so a separate black (K) is usually added. Red, green and blue are made from CMYK.
RGB and CMYK are two different color spaces. The RGB color space uses light in colors of red, green, and blue to create the visible spectrum. Our eyes see color in terms of reflected light, so the observed world is closer to RGB than CMYK. That is why native RGB devices that use light to create color, such as film recorders, scanners, and cameras can reproduce color fairly accurately.
Typical Color Spaces
Comparison of typical wide RGB gamut for a color accurate display, standard RGB gamut for an ordinary color display and a typical CMYK gamut for standard pigment inks.
The Adobe RGB profile reflects the wide RGB gamut, the sRGB profile reflects a standard RGB gamut.
Rendering IntentHandling Out-of-Gamut Colors
Standard Rendering Intents• Perceptual• Relative Colorimetric• Relative Colorimetric Black
Point Compensation• Absolute Colorimetric• Saturation
Rendering IntentPerceptual
• Relationships among colors are preserved• Color space is uniformly shifted• Absolute colors are not preserved • Technically reversible depending on RIP
Graphic to be printed
Printer
Rendering IntentAbsolute Colorimetric
• In gamut colors are preserved• Out of gamut colors are shifted• Not reversible
Graphic to be printed
Printer
Rendering IntentRelative Colorimetric
Optional Black Point Compensation
• Absolute Colorimetric with Compensation for White• Black Point Compensation also compensates for Black• In gamut colors are corrected for white and black points• Out of gamut colors are shifted • Black Point Compensation not supported on Adobe Output• Not reversible
Rendering IntentSaturation
• Only CIELAB Lightness or L* is preserved• All colors are shifted• Not reversible
Simple Color ManagementChromatic and Ink Limitation Clipping Causes Unpredictable Results
ICC Color ManagementStandards Based Approach to Achieving Predictable Color
Standard Adobe Design Environment
The standard Adobe design environment is RGB using the Adobe RGB color profile.
The target CMYK space is typically US Web Coated (SWOP) : an offset press.
Color Conversion Space
RGB
L*a*b*
CMYK
ICC Profiles Connect Design and Output SpacesUsing the L*a*b* Space as the Intermediary
Color Conversion Space
R G B L a b C M Y K34 74 141 17 16 -56 98 80 8 39
28 63 123 15 9 -46 97 79 14 58
4 48 97 12 3 -33 95 71 26 81
ICC Profiles are the basis for transforming color from the source space to the color conversion space and then to the printer. They can be thought of as tables that define conversions to and from L*a*b* space. Color values not in the table are interpolated.
Late BindingRGB devices will have distinctly different white and black points than CMYK output in relation to the colors that are produced.
Conversion between RGB and CMYK accounts for differences in gamut and white points. Optionally there can be compensation for differences in the black point. Late binding allows these to be mapped accurately to the final output device.
RGB Display Device CMYK on White Fabric
Output CMYK Color Mapping
Adobe RGB: 0 45 98
Dye Sublimation CMYK (Elvajet)Differs with Rendering Intent
Proprietary RIP algorithms also impact the color output.
Navy BluePantone 282
SWOP CMYK: 100 68 0 54
Absolute: 96 82 14 71Perceptual: 96 73 11 61Relative BPC: 94 65 10 71Relative: 95 80 17 75Saturation: 97 78 09 61
ICC Color ManagementStandards Based Approach to Achieving Predictable Color
Late binding: Design in RGB let RIP convert to CMYKModified late binding: Design in RGB and Named Colors
Pantone Spots
ICC Color ManagementStandards Based Approach to Achieving Predictable Color
Single EnvironmentTwo Profiles1. Printer Profile RGB to CMYK2. Named Color Profile
• RIP optionally bypasses printer profile and uses the named color formula if it exists.
• Unnamed colors should be specified in RGB.• Do not use raw CMYK specifications.
ICC Color ManagementLinearization: Controls Perceived Optical Density
45% color value1.25 optical density
1.25 optical density?? pixel value
ICC Color ManagementInk Limits: Improve Optical Density and Control Chromatic Shifts
MagentaCyanGray
RedBlueBlack
