Advanced color management Understanding color conversions ... · Advanced color management –...
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Advanced color management – Understanding color conversions and settings Lou Prestia Sr. Product Line Manager Heather Blakley Product Marketing Specialist
Transcript of Advanced color management Understanding color conversions ... · Advanced color management –...
Advanced color management –Understanding color conversions and settings
Lou PrestiaSr. Product Line Manager
Heather BlakleyProduct Marketing Specialist
Agenda
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• ICC color management basics
• Profile selection and embedded profiles
• PDF/X output intent
• Rendering intents
• Black point compensation
• Problems printing with black
• Color management failures
• Recommended DFE settings
Be sure to watch our previous webinars on color
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• 3 Key steps to get the right color the first try
• The ABCs of producing the best match for spot colors
• Best practices for matching industry color standards
ICC color management basics
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ICC color processing workflow
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How to access the expert color settings on your Fiery DFE
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Introducing the new Fiery Color Flow Chart
Profile selection and embedded profiles
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Embedded ICC profiles
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• Modern design applications favor the use of a “working space”
– Standard RGB or CMYK defined by ICC profile
– All files created are in a working space
• When saving from these applications, best practice is to embed profiles
Working spaces in Adobe Photoshop
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• Photoshop requires the definition of a working space for CMYK and one for RGB
• Photoshop does not force all windows to be in one of the working spaces
Photoshop color working space
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Profile mismatch
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• Photoshop provides warnings when opening and pasting about profile mismatches
Embed profile when saving
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Show assigned profile in Photoshop
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Working spaces in Adobe Illustrator
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• Uses working spaces
• Illustrator offers a unique profile mismatch option: “Preserve numbers”
– Causes Illustrator to ignore embedded profiles
Adobe Illustrator “Preserve numbers”
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X
Working spaces in Adobe InDesign
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• Uses working spaces
• InDesign allows the most latitude for mixed color spaces – every object on every page can have it’s own embedded profile
Image color settings in InDesign
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How to use working spaces on DFE
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• For documents you create, set the DFE color settings to match your working space
How to identify embedded profiles
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• From Adobe design applications
• Enfocus Pitstop
Checking embedded color space with Enfocus Pitstop
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Using embedded profiles on DFE
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Default Fiery color settings
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Use embedded profile
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PDF/X Output intent
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• Defined by the Ghent Working Group (GWG)
• Output Intent is a way to standardize the appearance of a PDF file
• Output Intent tag contains an ICC profile that is used as a simulation profile for both on-screen viewing and printing
ICC color processing workflow
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Using PDF/X Output Intent on the DFE
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PDF/X Output Intent - CMYK
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PDF/X Output Intent – RGB
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PDF/X output intent
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• Why not always always enable PDF/X Output intent?
– Over-compression of colors may occur
Rendering Intent
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What is gamut compression?
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• Loss of color gamut when converting from a broad gamut source space such as RGB to a more narrow output gamut such as CMYK
RGB
CMYK
What happens to colors outside reproducible color gamut of the printer?
RGB
CMYKRGB – Source gamutCMYK – Smaller destination gamut of printer
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Gamut Compression
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Rendering Intent
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• Setting that defines the preference for gamut compression
Rendering Intent: Photographic
RGB
Color 1
Color 2
Photographic (aka perceptual) –smooth color transitions; relationship preserved
RGB – Source gamutCMYK – Smaller destination gamut of printer
CMYK
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Color 1
Color 2
Rendering Intent: Relative Colorimetric
RGB
Color 1
Color 2
Relative Colorimetric –color accuracy for logos and graphics
RGB – Source gamutCMYK – Smaller destination gamut of printer
CMYK
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Color 1
Color 2
Relative colorimetric vs. photographic
37PhotographicRelative Colorimetric
Rendering Intent: Presentation
RGB
Color 1
Color 2
Presentation – aka “saturation” forbusiness graphics
RGB – Source gamutCMYK – Smaller destination gamut of printer
CMYK
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Color 1
Color 2
Rendering Intent: Absolute Colorimetric
RGB
Color 1
Color 2
Absolute Colorimetric –same as relative colorimetric with white point scaling for paper white
RGB – Source gamutCMYK – Smaller destination gamut of printer
CMYK
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Color 1
Color 2
Best uses of rendering intents
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• Photographic (aka perceptual) this rendering intent compresses the entries source gamut to fit in the destination gamut relationships between colors are preserved. Theoretically this is best for photographs.
• Relative Colorimetric this rendering intent compresses only the colors in the source gamut that are not also in the destination gamut. Best for logos and graphics.
• Presentation (aka saturation) this is the same as relative colorimetric but the colors in the destination gamut are all pushed toward the gamut corners where colors are pure. Best for business graphics.
• Absolute Colorimetric this is a special case of Relative Colorimetric. The color clipping is the same but the white point of the source is not scaled to the white point of the destination. This means the white of the source will be shown in the output as a tint even in non-image areas. This is mainly useful only for commercial proofing not for production printing.
Choosing rendering intent on the DFE
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RGB rendering intent
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CMYK rendering intent
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Always relative colorimetric!
Processing methods:
• Full (Source GCR)
• Full (Output GCR)
• Pure Primaries
Rendering intent when using embedded profiles
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Black point compensation
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Black point compensation
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• Maps the black point of the source profile to the black point of the output profile
– Helps to preserve detail in shadow areas
– Always desirable except for special applications such as proofing
Black point compensation
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Source = Newsprint ICC
Black point compensation
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Source = Newsprint ICC
For Proofing
Problems printing with black
Print Gray Using Black Only
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Color management black failure
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R=128
G=128
B=128
C=0%
M=0%
Y=0%
K =50%
L* = 62
a* = 0
b*= 0
L* = 58
a* = 0
b*= 0
C=40%
M=30%
Y=30%
K =20%
C=38%
M=27%
Y=27%
K =22%
DFE settings to avoid this failure
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• To ensure you don’t get a color click charge for black objects (K only output)
– Set RGB to: Text/Graphics
– Set CMYK to: Text/Graphics/Images
Pure black
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• Pure black is RGB of 0,0,0 or CMYK of 0,0,0,100%
Black overprint
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• Black overprint (for pure black)
– Use to trap text
Color management failures
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Common causes for color management failure
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• Calibration
• Imaging settings
• Color Settings
– Output Profile selection
• Lighting
Calibration: Accuracy vs. Consistency
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Ca
lib
rate
dConsistent, but
not Accurate Color
Consistent, and Accurate
Color
Without ICC Profile
Un
cali
bra
ted
Neither consistent nor Accurate Color
With ICC Profile
Accurate on average,not consistent
Calibration
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• Over 30% of digital press owners never calibrate their DFE or only calibrate when a color failure occurs *
• Failure to calibrate on a consistent basis is the #1 cause of color related rework
* Source: 2015 InfoTrends survey
DFE settings
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1. Imaging settings
2. Source profile settings
3. Output profile selection
– Is it a custom profile?
1. Image settings
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2. Source profile settings
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3. Output profile selection
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• Depending on the configuration of the DFE, output profile may be selected automatically or manually
Start
Job Properties“Use Media
Defined Profile” selected?
Automatic output profile selection
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Automatic output profile selection
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Start
Job Properties“Use Media
Defined Profile” selected?
Yes
Is Paper Catalog used in
the job?
Automatic output profile selection
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Automatic output profile selection
Start
Job Properties“Use Media
Defined Profile” selected?
Yes
Is Paper Catalog used in
the job?
Profile assignedin Paper Catalog?
Yes
Automatic output profile selection
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Automatic output profile selection
Start
Job Properties“Use Media
Defined Profile” selected?
Output profile assignedin Paper catalog
Yes
Is Paper Catalog used in
the job?
Profile assignedin Paper Catalog?
Yes
Yes
Automatic output profile selection
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Start
Job Properties“Use Media
Defined Profile” selected?
Output profile assignedin Paper catalog
Yes
Is Paper Catalog used in
the job?
Profile assignedin Paper Catalog?
Is a Profile assigned tothe paper
type?
Yes
No Yes
Automatic output profile selection
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Automatic output profile selection
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Automatic output profile selection
Start
Job Properties“Use Media
Defined Profile” selected?
Output profile assignedin Paper catalog
Output profile assignedto paper type
Yes
Is Paper Catalog used in
the job?
Profile assignedin Paper Catalog?
Is a Profile assigned tothe paper
type?
YesYes
No Yes
Automatic output profile selection
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Start
Job Properties“Use Media
Defined Profile” selected?
Output profile assignedin Paper catalog
Output profile assignedto paper type
Yes
Is Paper Catalog used in
the job?
Profile assignedin Paper Catalog?
Is a Profile assigned tothe paper
type?
YesYes
No
No Yes
Automatic output profile selection
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Start
Job Properties“Use Media
Defined Profile” selected?
Output profile assignedin Paper catalog
Color settings default profile
Output profile assignedto paper type
Yes
Is Paper Catalog used in
the job?
Profile assignedin Paper Catalog?
Is a Profile assigned tothe paper
type?
No
YesYes
No
No Yes
Automatic output profile selection
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Start
Job Properties“Use Media
Defined Profile” selected?
Output profile selected in Job properties
Output profile assignedin Paper catalog
Color settings default profile
Output profile assignedto paper type
No Yes
Is Paper Catalog used in
the job?
Profile assignedin Paper Catalog?
Is a Profile assigned tothe paper
type?
No
YesYes
No
No Yes
Automatic output profile selection
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Lighting and metamerism
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• Understanding metamerism
• New ISO viewing conditions
– M0, M1 and M2
Metamerism
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• Two colors that look the same under one light source but different under another
Metamerism: Different light source
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R G B
Wavelength (nm)
Viewing color in D50 light booth
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• Color management only works in D50
Lighting best practices
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• Only evaluate prints in D50 light booth
• Use professional grade ISO 3664:2009 compliant lamps
• For best results, profile and verify color using M1
Recommended DFE settings
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What we learned
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• ICC color management basics
• Profile selection and embedded profiles
• PDF/X output intent
• Rendering intents
• Black point compensation
• Problems printing with black
• Color management failures
• Recommended DFE settings
Resources
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• Fiery Color Flowchart 2016 and video• Fiery Color Profiler Suite webpage
– Learn about features, watch videos, download resourcesand a free demo
– How-to guides– Whitepapers
• Configuring Fiery color settings to optimize print quality• Demystifying color standards
– FAQ: to cut or not to cut UV light in color profiling• Download PANTONE libraries• Ask the experts on our forums:
– Fiery Color and Imaging– Fiery Color Profiler Suite
