What is Color Management

Why do we need it?

Andrew Rodney aka The Digital Dogwww.digitaldog.netandrew@digitaldog.net

What is Color Management ?

• The ability to accurately and predictably control the reproduction of color from beginning to end.

• For the following presentation ICC Color Management will be covered.

Color Management Does Not

Fix bad color, especially bad originals.GIGO - Garbage In - Garbage Out.

Device Dependent Color

• Device dependant color is a recipe for color.• RGB & CMYK describe an ingredient for color,

NOT how it looks! • RGB to RGB and CMYK to CMYK conversions are

necessary.• RGB needs to be optimized for each printer just

like CMYK.

Device Dependent Color

Color Appearance is the same but numbers are NOT

Same numbers without the display profile will preview incorrectly!

Gamut• Gamut is the range of

color that a device or process can produce

• Devices vary widely on gamut they can reproduce.

• Better to have proofing device have wider gamut than gamut of final output device.

•

Color Gamut & Color Management

• We can create 16.7 million color (24 bit).• We can see approximately 12 million colors.• Typical 4 color press can produce 70,000 colors.•

ICC profiles have 4 Rendering Intents:Perceptual (images)

Relative Colorimetric Absolute Colorimetric (proofing)

Saturation (graphics)

Calibration vs. Profiling

• Calibration places devices into a known and repeatable state.

• Profiling “fingerprints” the behavior of the device. • ALL devices should be calibrated! We can’t work with

uncalibrated devices either with, or without ICC Color Management!

How does a CMS work?ICC profiles describe the conditions

of ALL our devices• Device profiles use device independent color to

translate color from device to device.• Profiles are generated using empirical data from

Spectrophotometers and Colorimeters after reading color data from our devices.

Profiling Overview

• Profile camera/scanner.• Calibrate and profile monitor.• Profile proofing device.• Profile output device.• Use profiles in production (Photoshop 7 in this

session).

Profiling Scanner

IT-8 Target

Profiling Scanners

• Using IT8, Transparencies and Reflective only. No profiling of color negs at this time.

• Scanner must be able to be placed into a consistent state! Auto corrections invalidate process unless scanner is ICC savvy.

• Scanner should support high bit file saving for applying profile after the scan or should support ICC profiles at the scan stage.

Profiling Digital Camera

• Current solutions work best in studio situations (Maybe not)...

• May need different profiles for different subjects (Maybe not)…

• Extremely dependent on consistency.• Difficult to include target in all shots.• Works best if capturing at high bit depth.• Most use Macbeth ColorChecker as target.•

Profiling Digital CameraTargets...

NEW Macbeth ColorChecker

Monitor Calibration Considerations

• Allow monitor to warm up at least one hour before calibrating (Barco is an exception).

• Shield from extraneous light (hood).• After calibrating do not make adjustments to

monitor (keepa your hands off).• Look for monitors with controls over the RGB Guns.

Measuring Instruments - Monitor

• Spectrolino - GretagMacbeth• Eye-One - GretagMacbet• Eye-One Display - GretagMacbeth (NEW)• Monitor Optimizer DTP 92 - X-Rite• Monitor Calibrator - Minolta• Color Vision Spyder• Optix - Monaco

Monitor Calibration Software

• OptiCal 3 - ColorVision*• PhotoCal - ColorVision*• Eye-One Match - GretagMacbeth*• ColorSynergy 4.1 - Pictographics• ColorBlind - ITEC/Color Solutions• ViewOpen - Heidelberg*• Monaco EZ Color - Monaco Systems*• ColorFlow “Family” - Kodak• ProveIt - ITEC/Color Solutions• ICC Capture -Profile City/BasICColor*

*OSX compatible

• Built in monitor controls - $0• ColorSync 3 to calibrate & profile - $0• Adobe Gamma control panel - $0• Calibration software & hardware - $300 to $700• Sony Artisan, Barco Calibrator, Mitsubishi

SpectraView, LaCie Blue Eye - $1,200 to $5,000

Monitor Calibration Costs

Output Profiling Solutions

• ColorBlind Pro - ITEC/Color Solutions• Matchbox - ITEC/Color Solutions• PrintOpen - Heidelberg*• MonacoPrint & Proof- Monaco Systems*• Monaco EZ Color 1.3.4 - Monaco Systems*• ProfileMaker Pro - GretagMacbeth*• Eye-One Match - GretagMacbeth*

*OSX compatible

Output Profiling Solutions

• Compass Profile Printer - Praxisoft• WSIWIG - Praxisoft• ColorFlow - Kodak• ColorSynergy - Pictographics• ProfilerPro - Color Vision*• BasICColor- ICS/Profile City*• Profile Wizard - Creo Scitex• ColorKit - Fuji*

*OSX compatible

Profiling Software Considerations

• Support for your measuring device• Ease of use and documentation• Control of black generation• Options including HiFi and Hexachrome• Ability to edit profiles• Technical support• Compatibility with your OS

Measuring Instrument Types

• Densitometer– measures the amount of light absorption

• Colorimeter– measures light by breaking it into its RGB

components• Spectrophotometer

– measures spectral data–the amount of light energy reflected from an object

Measuring Instrument Costs

• Densitometers– $500 to $3,000

• Colorimeters– $249 to $3,000

• Spectrophotometers (depends on features)– $900 to $6,000

ICC profile transforms require we specify a Source and Destination profile

Each device “speaks” it’s own language. Profiles are translators for describing each

device to each other!

Scanner RGB Working Space RGB

Working Space RGB Printer RGB

Working Space RGB Printer CMYK

In an ICC workflow, there has to be a Source and Destination transform!

Colorspace conversions are necessary! Files are then optimized

for specific output needs

ColorMatch RGB SWOP Coated

SWOP Coated Iris Proofer

ColorMatch RGB Epson 2200 Glossy

One file may make many colorspace transformations!Scanner to Working Space, Working Space to multipleoutput devices with different gamuts and colorspaces

(RGB and/or CMYK) known as retargeting

Photoshop 5.0 to 7.0 uncouples the monitor from the editing process

• Editing is NOT based on the idiosyncrasies of a monitor

• All images perceptually identical thanks to RGB Working Spaces & Display profile

•

Monitor RGB (Device Dependent)

RGB Working Space (Adobe 1998)Quasi-Device Independent

Display Using Monitor Compensation

• Since the Working Spaces are identical among all users, what about the display?

• The ICC profile that describes your display is used to compensate and make everyone see the same previews.

• Photoshop does an on-the-fly conversion from Working Space to monitor.

• Display Using Monitor Compensation is always on in Photoshop 6 and 7!

Display Using Monitor Compensation

7 units too blue 7 units too Yellow

So, What’s all the Fuss about Photoshop 6 & 7?

• Document-Specific Color. Users can now open multiple files in multiple color spaces at the same time and each preview is correct.

• Profile Embedding is now correctly implemented. Any assigned profile is written to the file.

• RGB Soft proof is now possible. Multiple soft proof previews can be open at one time.

So, What’s all the Fuss about Photoshop 6 &7 ?

• Conversions using “Convert to Profile” or Mode Change are identical.

• Assign Profile command to control what profiles get used for each file.

• 3 main policies for altering the default behavior of the Color Settings.

•

RGB Working SpacesWhich one?

• sRGB . Smallest Gamut. Good for the web• ColorMatch RGB . Good for PressView users or

those with calibrated displays and lots of legacy files. Good for 4-color output, but shy in the cyans.

• Adobe 1998. Good gamut for most output but larger than the gamut of our displays which could produce unexpected results.

• Wide Gamut RGB. Contains the Ektachrome gamut but very wide. Not appropriate for 8 bit editing. Many colors outside display gamut!

RGB Working Spaces:Custom

• Don’t attempt to alter the RGB Working Spaces (like changing gamma) or the space will become “custom” and likely incorrect!

• Custom Spaces (Bruce RGB, ProPhoto RGB etc) These spaces can work well but be aware that sharing files with others who don’t have these spaces (saved as ICC profiles) opens up lots of problems but less so in Photoshop 6 (due to document specific color features).

•

Photoshop Color Settings Policies

• Control the default behavior files that don’t match the “Working Space.”

• Preserve Policy provides the most flexibility for users that work with many color spaces.

• Convert Policy attempts to “force” the Working Space upon files that don’t match.

• Off Policy is not recommended.

Photoshop Color Settings Working Space- RGB

• Make sure your monitor profile is being seen by Photoshop. In the RGB Working Space popup, the name should be seen as next to “Monitor RGB” heading.

•

• Pick a hard-wired RGB Working Space ColorMatch RGB or Adobe 1998 are two good editing spaces for most users.

•

Photoshop Color Settings Working Space- CMYK

• Simply load the ICC profile for the CMYK output device you wish to print to.

• Conversions can be carried out using “Convert to Profile” or using the standard Mode change “CMYK” menu. Rendering intents can be previewed prior to conversion using “Convert to Profile” along with paper and ink simulation

Photoshop Color Settings Working Space- Grayscale

• Use Gamma settings for output to screen or dot gain to match specifics of output device

• Existing CMYK ICC profiles can also be loaded so the black generation of that profile is used for conversions.

• Custom settings for everyone else...

Photoshop Settings-Warnings

• Set Behavior of Photoshop’s Warnings.• Have the Ask checkboxes on to warn about Missing

Profiles, Profile Mismatches or Paste Mismatches. • For more details on the settings refer to the

Photoshop PDF’s on www.digitaldog.net

Miscellaneous items to consider

• Monitor Gamma isn’t Working Space Gamma• Keep environmental conditions in mind: Have a lightbox, control lighting, control colors nearby.

• Create test files for evaluating your output:Memory colors, gray ramps, typical kinds of work etc.

• Cases you may NOT want to embed profile:Service bureau doesn’t understand them. Beware of SB’s that expect you to alter YOUR display to match their output.

Benefits of a CMS:• Predictable, Repeatable & Accurate Color.• Good Soft Proofing on screen for editing• Empirical Data (numbers).• Ability to make multiple devices match (Know as Cross Rendering).

• Robust Gamut Mapping• Non Ambiguous File origins using ICC profiles

(profile embedding).