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
Dye Sublimation Color Management
Achieving Accurate Color Output Using Standardized ProcessesColor GamutDefinition 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. 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 IntentsPerceptualRelative ColorimetricRelative Colorimetric Black Point CompensationAbsolute ColorimetricSaturationRendering IntentPerceptual
Relationships among colors are preservedColor space is uniformly shiftedAbsolute colors are not preserved Technically reversible depending on RIPGraphic to be printedPrinter
Rendering IntentAbsolute Colorimetric
In gamut colors are preservedOut of gamut colors are shiftedNot reversible Graphic to be printedPrinterRendering IntentRelative ColorimetricOptional Black Point Compensation
Absolute Colorimetric with Compensation for WhiteBlack Point Compensation also compensates for BlackIn gamut colors are corrected for white and black pointsOut of gamut colors are shifted Black Point Compensation not supported on Adobe OutputNot reversible
Only CIELAB Lightness or L* is preservedAll colors are shiftedNot reversibleSimple Color Management
Chromatic and Ink Limitation Clipping Causes Unpredictable ResultsICC Color Management
Standards Based Approach to Achieving Predictable ColorStandard 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
RGBL*a*b*CMYKICC Profiles Connect Design and Output SpacesUsing the L*a*b* Space as the Intermediary 13Color Conversion Space
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. 14Late 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 DeviceCMYK on White FabricOutput CMYK Color MappingAdobe RGB: 0 45 98
Dye Sublimation CMYK (Elvajet)Differs with Rendering Intent
Proprietary RIP algorithms also impact the color output.
Navy BluePantone 282SWOP CMYK: 100 68 0 54Absolute: 96 82 14 71Perceptual: 96 73 11 61Relative BPC: 94 65 10 71Relative: 95 80 17 75Saturation: 97 78 09 6116ICC Color Management
Standards Based Approach to Achieving Predictable ColorLate binding: Design in RGB let RIP convert to CMYKModified late binding: Design in RGB and Named Colors
Pantone SpotsICC Color ManagementStandards Based Approach to Achieving Predictable ColorSingle EnvironmentTwo ProfilesPrinter Profile RGB to CMYKNamed 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 density1.25 optical density?? pixel valueICC Color ManagementInk Limits: Improve Optical Density and Control Chromatic Shifts