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Introduction to
Color ManagementPart 1
Photographers of VashonFebruary 28, 2008
POV Intro to Color Management 2
Purposes of Presentation
• Educate POV members about current digital practices and their benefits
• Begin building a shared vocabulary of standards within POV
• Increase the technical quality of our artwork for forthcoming exhibitions and personal applications
• Enable POV to further educate community members
POV Intro to Color Management 3
Learning Objectives
By the end of this presentation you will have a greater understanding of:• The benefits of using a color-managed
workflow for processing digital images• Computer-based digital devices and their
corresponding profiles• Key terms and their definitions• Standard color management tools
POV Intro to Color Management 4
Organization of Presentation
This presentation covers a lot of material--both definitions and practical applications of color management. Practices that will provide immediate benefit to your digital processing workflow are highlighted by “High Priority” checkmarks
POV Intro to Color Management 5
What Is A Digital Workflow?
Workflow is a term used to describe the sequence of activities, people, data, and tools required to produce a desired output in digital photography.>Workflow focuses on process rather than documents.
POV Intro to Color Management 6
POV Intro to Color Management 7
What Is Color Management?
Color management encompasses a set of software technologies that seeks to match color across input, display, and output devices by referencing their color behavior to a known standard by means of device profiles.
POV Intro to Color Management 8
Why Color Management? (1)
Color management• Helps ensure consistency among all these devices • Minimizes the perceived differences in displayed colors
between devices
Obtaining predictable color reproduction in the
digital darkroom can be a challenge because each device--digital camera, scanner, monitor, or
printer--responds to or produces color differently.
POV Intro to Color Management 9
POV Intro to Color Management 10
Why Color Management? (2)A color-managed workflow can help you. . .Improve the color match between your monitor
and printer. Achieve satisfying results with fine art papers or
nonstandard inks, for example, from independent manufacturers.
Send out an image to be printed accurately on a large format printer at a service bureau or Costco.
Reproduce color as precisely as possible-- for example, for fashion, weddings, or art reproduction.
POV Intro to Color Management 11
Color Management FoundationTwo key elements of color management:ICC profiles: data that define color in
devices (digital cameras, printers, scanners, monitors) or image color spaces (sRGB, Adobe RGB 1998, ProPhoto RGB).
Gamut mapping: the ability of color information to be transferred from one device (or color space) to another. From an image on a memory card to a monitor From Adobe RGB to sRGB color spaces
POV Intro to Color Management 12
Definitions (1)1. ICC (International Color
Consortium): Hardware and software vendors dedicated to developing cross-platform standards for color communication and consistency.
2. Color space: A three-dimensional representation of the colors that can be produced by a color model.
3. Gamut: The range of color a device can produce.
sRGB vs. Adobe RGB color space
POV Intro to Color Management 13
Profiles vs. Color Spaces
• Profiles are for devices • Color spaces are for images
POV Intro to Color Management 14
Color-Managed Workflow Strategy
Use ICC-aware tools to recognize color spaces and device profiles, and apply gamut mapping when moving images among the devices!
POV Intro to Color Management 15
The Difficult Parts•Learning a new language•Learning new tools •Obtaining or creating profiles•Evaluating quality•Setting up smart workflows•Documenting your workflow•Balancing your artistic good sense with what the computer shows you
POV Intro to Color Management 16
Mac vs. Windows Differences
• ICC standards based on ColorSync• All Mac applications(Word/Photoshop/Mail) reflect
consistent color management• Windows XP - Image Color Management (ICM)
http://www.microsoft.com/windowsxp/using/digitalphotography/prophoto/colorcontrol.mspx
• Color monitor calibration tools work fine in XP• Not all Windows applications show consistent
color in XP• Vista fixes this:
http://www.microsoft.com/prophoto/articles/colormgmt.aspx
• Both OS’s equally capable with color management• Apple pioneered ColorSync color management
system that is built into Mac OS-X
POV Intro to Color Management 17
Start with the monitor
• A calibrated monitor is your stake in the ground.• Calibration adjusts the monitor to a specific color
temperature, gamma, and black & white luminance.
• Calibration produces a display profile.• The calibration software works with your
computer’s operating system to default to the same display profile every time you use your computer.
POV Intro to Color Management 18
Definitions (2)1. Color temperature: A measurement of the color of
white light, expressed in Kelvins. Computer monitors typically have a color temperature of 5000-9300K: 5000K= yellowish-white, 9300K=blue white. 6500K is recommended
2. Gamma: describes the reflectance of your prints. Gamma affects middle tones; it has no effect on black or white. Too high gamma = too dark middle tones appear. Too low gamma = too light middle tones. 2.2 is standard gamma for displays today.
3. Black & white luminance: the amount of light or dark of a defined area
POV Intro to Color Management 19
Display Calibration Benefits• Enables Photoshop
color consistency• Prerequisite for
printer accuracy• Improves the look of
everything on your computer
• Tones down too-bright LCD mfgr. presets
POV Intro to Color Management 20
Display Calibration Issues
• Don’t confuse display profile with color space– Often software will display one long confusing list
of all profiles and color spaces – Name your display profile for yourself
• CRTs burn out after 6 years• Calibrate in near dimly lighted room
– Indirect lighting will help accuracy• http://www.gballard.net/boutique/colorcorrecting.html
POV Intro to Color Management 21
Display Calibration Methods• Estimating with system software
– Mac ColorSync display utility– Adobe Gamma for Windows
in Photoshop• Specific software-only calibration
– Supercal is OK• Hardware device with matching software
– Spyder, Monaco, XRite etc. colorimeter pucks hang off displays, take measurements and create custom profile. $200-500
– Dedicated software works with pucks; all are good.
– Color Eyes Display works with multiple pucks, is superior software, and is expensive.
• Colorimeters also used for calibrating HDTVs
Less effective
More effective
POV Intro to Color Management 22
You Must Use Printer Profiles
• Accurate monitor + printer profiles = prints that closely match what you see on your monitor.
• Without profiles, you need to rely on trial and error, guessing, and luck.
• Printer profiles are easy to obtain and use.• Most of you use them in Photoshop now.
POV Intro to Color Management 23
Photoshop Print With Preview Options
Image color space
Rendering Intent
Printer profile
Sets CS2 to manage
color
POV Intro to Color Management 24
Definitions (3)1. Rendering intent: methods and rules for
converting colors from one color space to another.The four ICC specified rendering intents are discussed on next slide.
2. Out-of-gamut colors: colors present in the source color space that the destination color space or profile cannot reproduce. Example: A deep green in the image file that a printer cannot reproduce precisely.
POV Intro to Color Management 25
Definitions (4)1. White Balance: a reference point which represents
white that is required by digital cameras. All other colors are then calculated based on the white point.
2. Hue: a dimension of color we readily experience when we look at color. How well individual colors can be distinguished in an image.
3. Saturation: the dominance of hue in the color. Desaturated colors become more gray.
4. Lightness: Also known as value, how light or dark a color is--its intensity.
A nice reference:http://www.ncsu.edu/scivis/lessons/colormodels/color_models2.html#hue.
POV Intro to Color Management 26
Relative Colorimetric Rendering
Relative Colorimetric--produces superior results generally.How it works: first scales the white of the source space to the white of the target space, adjusting all other colors relative to that white. Then it matches the adjusted colors in the source space that are inside the gamut of the target space exactly, and clips out-of-gamut colors to the nearest reproducible hue, sacrificing lightness and saturation.
POV Intro to Color Management 27
Perceptual RenderingPerceptual – good for images with significant shadow details where a slight lightening of the print is acceptable to open up the shadows. Also images with areas of highly saturated color can benefit from Perceptual rendering. If you see color banding in the soft proof with relative colorimetric selected, try perceptual. How it works: attempts to compress the gamut of the source space into the gamut of the destination space -- even though all the colors may change in the process.
POV Intro to Color Management 28
Absolute Colorimetric Rendering
Absolute Colorimetric--used to simulate an output on your monitor or on your proofing system (soft proofing). Useful for visualizing what a printing service will produce.How it works: scales the white of the destination space to the white of the source space
POV Intro to Color Management 29
Saturation Rendering
Saturation--least used intent; Useful for cartoons, comics, business graphics. How it works: Saturation rendering maps fully-saturated colors in the source space to fully saturated colors in the target space, sacrificing hue and lightness.
POV Intro to Color Management 30
Obtaining Printer Profiles
Most printer profiles come with the software drivers that you install after purchasing the printer. Also available online at the support site of the mfgr.Some printer profiles are pre-installed on your computer. These appear in when you browse to add a printer.
Get more profiles
Existing profiles
POV Intro to Color Management 31
Paper Profiles Matter
• Accurate paper profiles+printer profiles = richer prints that closely match what you see on your monitor.
• Ink will lay on paper as intended with artful grain patterns.
• Without profiles, you need to rely on trial and error, guessing, and luck.
• Paper profiles are easy to obtain and use.• Some may be substituted for others, but it
requires trial and error.
POV Intro to Color Management 32
Using Installed Paper Profiles (1)
1. Paper profiles are accessed via the Print dialog box.
2. Profiles are listed in the Presets
dropdown menu• Give profiles your own names using the
Save As function
POV Intro to Color Management 33
Using Installed Paper Profiles (2)
Paper and ink configurations are accessed via the
3rd dropdown menu.
• Not intuitive interface on Macs!
POV Intro to Color Management 34
Obtaining 3rd-Party Paper Profiles
• Sometimes available from printer mfgr website
• Paper mfgrs usually provide downloads on their websites
• Newer printers may not yet have paper profiles
• Some OEM profiles can be successfully substituted for branded ones– Ilford for Costco or Staples
POV Intro to Color Management 35
Obtaining Pro Photo Lab Profiles
• Dry Creek Photo provides printer and paper profiles online for soft proofing for– All Costco stores– Many pro labs including
Panda and Capitol Hill Photo
• Other lab websites often callout standard profiles or will provide upon request
• Dry Creek and others also can create custom ICC printer profiles for your own setup
• http://www.drycreekphoto.com/icc/
POV Intro to Color Management 36
Basic Color Management in Photoshop
• Photoshop can be completely color managed• Workflow starts when images are imported• Be consistent with use of color spaces and
profiles• Begin with the end in mind
– Know the delivery targets for your images• Paper• Website• Magazine• Poster
POV Intro to Color Management 37
Assigning Color Space in Photoshop (1)
Photoshop assigns your desired color space when images are imported.• Adobe RGB (1998) is preferred for studio inkjet printers
• sRGB is critical for web-based images• Check the requirements for pro printing services
POV Intro to Color Management 38
Assigning Color Space in Photoshop (2)
1. In CS2, choose Color Settings under the Edit menu. Adobe RGB (1998) is preferred for studio inkjet printers
POV Intro to Color Management 39
Assigning Color Space in Photoshop (3)
1. For studio printing, replicate these settings in the dialog box.
2. For web delivery, change the topmost setting to North America Web/ Internet
POV Intro to Color Management 40
Color Space Mismatches in Photoshop
1. Color management mismatches can trigger profile warnings upon copy/pasting images that don’t match your desired color space.
2. The preference box lets you choose between using one of two color spaces or zero color management
POV Intro to Color Management 41
Assigning Color Space in PhotoshopYou can also change color spaces of image files within CS2.• Choosing a different Profile button
dropdown menu assigns the new profile to the image without converting colors to the profile space. This may dramatically change the appearance of the colors as displayed on your monitor.
This is useful when an image is missing its profile or has an incorrect embedded profileYou can also remove a profile by clicking on the Don’t Color Manage This document button.
POV Intro to Color Management 42
Converting Color Space in Photoshop
CS2 allows you to “Convert” the color spaces of images. This is different from “Assigning” a color space.• Choosing Convert to Profile
changes the image’s colors to the new color space This will dramatically change the appearance of the colors as displayed on your monitor.
Conversion allows you to edit in one color space and then convert to another. • Ex. soft proofing an image to see
how it will appear in a different output environment, such as a pro printing service or Costco.
POV Intro to Color Management 43
And What About Lightroom?
Adobe Lightroom’s default color space is ProPhoto RGB, the largest one available.You can configure Lightroom to export images to sRGB or Adobe RGB color spaces.
Images going from Lightroom to Photoshop for more editing can be exported in any of the three color spaces.
POV Intro to Color Management 44
Color Management and the Internet
• HP and Microsoft pioneered web colors• sRBG is de facto color space for web• Limitations
– Browser issues; lowest common denominator viewer
– Never embed Adobe RGB in Internet images– Only a few browsers (Safari, OmniWeb) are color
managed• http://www.gballard.net/psd/go_live_page_profile/
embeddedJPEGprofiles.html
– Computer OS color management system makes an inaccurate assumption about the source file
POV Intro to Color Management 45
Color Spaces and Your Camera
Many cameras allow setting of color spaces• Color space menu settings only relevant
for .jpg files– RAW files are unaffected– RAW files will be set to desired color space
when importing into Photoshop or Lightroom• You can go from Adobe RBG to sRBG, but
not the other way– Set color space to Adobe RBG and then assign
when needed– If you are shooting for web only, use sRGB
POV Intro to Color Management 46
Consider Calibrating Your Camera
•Ensures more consistent color from the camera’s images in Photoshop and Lightroom
– more accurate hue and saturation•Once specific calibration presets are
developed, using them is a one-click process in Photoshop and Lightroom
•This calibration is not directly related to ICC calibrated profiles.
POV Intro to Color Management 47
Definitions (5)1. Firmware: is software that operates a
hardware device and is stored on the flash memory of the device. Can be updated.Ex. DSLRs have firmware upgrades to fix bugs or provide new functions.
2. CCD sensor: charge-coupled device used by many digital cameras to read the intensity of light.
3. CMOS sensor: Complementary metal–oxide– semiconductor used by many digital cameras to read the intensity of light.
POV Intro to Color Management 48
How Camera Calibration Works• CS2 & Lightroom use two built-in profiles for each
supported model of camera when it interprets image data.
• Profiles are produced by photographing a color target under different white-balanced lighting conditions. When you set a white balance, software uses the profiles for your camera to extrapolate color information.
• These camera-specific profiles are generic, derived from baseline units.
• Your camera may be different from baseline units due to design and firmware changes.
POV Intro to Color Management 49
Software Calibration Presets
Presets in Photoshop
Adobe Camera Raw and
Lightroom allow you to tweak the interpretation of
color to better match the
characteristics of your camera and
CCD/CMOS processing chip.
Calibration tab in CS2 ACR
Calibration slider in Lightroom
Lightroom user presets
ProfileProfile
User tweaks
POV Intro to Color Management 50
Obtaining Calibration Presets
The purist process for properly calibrating your camera requires
technical equipment and skills beyond our scope.
The easy way: search for “camera calibration” in online
camera- specific forums such as dpreview.com or photo.net. Or
post a query there.Then compile the various
configurations as settings or presets and determine which one
works best for your camera or aesthetic.
Calibration slider in Lightroom
Lightroom user presets
Profile
Each preset is slightly
different
POV Intro to Color Management 51
Scanner CalibrationScanner profiles ensure accurate and consistent color and density captures. Scanning calibration can be done on your scanner using an industry standard reference chart called an IT8 Target.You scan the target and then use profile creation software to read the data and build a custom profile.After the profile is created, you then assign it to newly scanned images as they are imported into Photoshop.
POV Intro to Color Management 52
Scanner Calibration Tips• Allow your scanner to warm up before creating
a profile - 20 minutes should do.• Handle the IT8 target carefully and keep it in a
dark folder to avoid fading.• Different profiles need to be created for
reflective scans and transparency scans.• Create a new profile if you change the lamp or
if you have inconsistent results.• Keep the scanner’s glass surface clean.• Always check for scanner firmware and
software updates
POV Intro to Color Management 53
Five Most Important CM Practices
1. Calibrate your monitor2. Use printer & paper profiles3. Document your workflow
regularly4. Use the right color spaces for
the right job5. Observe the art in your work
POV Intro to Color Management 54
Valuable CM Resources1. Making fine prints in your digital darkroom, Norman Koren
• http://www.normankoren.com/makingfineprints.html2. Andrew Rodney’s Digital Dog
• http://www.digitaldog.net/3. CreativePro Books
• http://www.creativepro.com/eservices/bookstore/4. Cambridge in Color
• http://www.cambridgeincolour.com/tutorials/color-management1.htm
5. Adobe CM Terminology• http://kb.adobe.com/selfservice/viewContent.do?
externalId=320624&sliceId=26. Martin Evening Books
• http://kb.adobe.com/selfservice/viewContent.do?externalId=320624&sliceId=2