Introduction to Color Management Part 1

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Introduction to Color ManagementPart 1

• Photographers of Vashon
• February 28, 2008

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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

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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

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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

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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.
• gtWorkflow focuses on process rather than
  documents.

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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.

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Why Color Management? (1)
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.

• Color management
• Helps ensure consistency among all these devices
  
• Minimizes the perceived differences in displayed
  colors between devices

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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.

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Color Management Foundation

• Two 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

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Definitions (1)

• ICC (International Color Consortium) Hardware
  and software vendors dedicated to developing
  cross-platform standards for color communication
  and consistency.
• Color space A three-dimensional representation
  of the colors that can be produced by a color
  model.
• Gamut The range of color a device can produce.

sRGB vs. Adobe RGB color space
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Profiles vs. Color Spaces

• Profiles are for devices
• Color spaces are for images

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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!

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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

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Mac vs. Windows Differences

• Both OSs equally capable with color management
• Apple pioneered ColorSync color management system
  that is built into Mac OS-X

• 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/digitalph
  otography/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/prophot
  o/articles/colormgmt.aspx

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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
  computers operating system to default to the
  same display profile every time you use your
  computer.

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Definitions (2)

• 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, 9300Kblue
  white. 6500K is recommended
• 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.
• Black white luminance the amount of light or
  dark of a defined area

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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

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Display Calibration Issues

• Dont 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.h
  tml

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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

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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.

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Photoshop Print With Preview Options
Image color space
Rendering Intent
Sets CS2 to manage color
Printer profile
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Definitions (3)

• 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.
• 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.

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Definitions (4)

• 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.
• Hue a dimension of color we readily experience
  when we look at color. How well individual colors
  can be distinguished in an image.
• Saturation the dominance of hue in the color.
  Desaturated colors become more gray.
• Lightness Also known as value, how light or dark
  a color is--its intensity.
• A nice reference
• http//www.ncsu.edu/scivis/lessons/colormodels/col
  or_models2.htmlhue.

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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.

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Perceptual Rendering

• Perceptual 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.

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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

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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.

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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
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Paper Profiles Matter

• Accurate paper profilesprinter 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.

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Using Installed Paper Profiles (1)

• Paper profiles are accessed via the Print dialog
  box.
• Profiles are listed in the Presets dropdown menu
• Give profiles your own names using the Save As
  function

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Using Installed Paper Profiles (2)

• Paper and ink configurations are accessed via the
  3rd dropdown menu.
• Not intuitive interface on Macs!

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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

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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/

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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

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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

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Assigning Color Space in Photoshop (2)

• In CS2, choose Color Settings under the Edit
  menu. Adobe RGB (1998) is preferred for studio
  inkjet printers

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Assigning Color Space in Photoshop (3)

• For studio printing, replicate these settings in
  the dialog box.
• For web delivery, change the topmost setting to
  North America Web/ Internet

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Color Space Mismatches in Photoshop

• Color management mismatches can trigger profile
  warnings upon copy/pasting images that dont
  match your desired color space.
• The preference box lets you choose between using
  one of two color spaces or zero color management

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Assigning Color Space in Photoshop

• You 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 profile
• You can also remove a profile by clicking on the
  Dont Color Manage This document button.

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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 images
  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.

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And What About Lightroom?

• Adobe Lightrooms 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.

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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/e
  mbeddedJPEGprofiles.html
• Computer OS color management system makes an
  inaccurate assumption about the source file

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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

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Consider Calibrating Your Camera

• Ensures more consistent color from the cameras
  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.

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Definitions (5)

• 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.
• CCD sensor charge-coupled device used by many
  digital cameras to read the intensity of light.
• CMOS sensor Complementary metaloxide
  semiconductor used by many digital cameras to
  read the intensity of light.

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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.

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Software Calibration Presets
Profile
Profile

• 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 slider in Lightroom
User tweaks
Calibration tab in CS2 ACR
Lightroom user presets
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Obtaining Calibration Presets
Profile

• 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
Each preset is slightly different
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Scanner Calibration

• Scanner 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.
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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 scanners glass surface clean.
• Always check for scanner firmware and software
  updates

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Five Most Important CM Practices

• Calibrate your monitor
• Use printer paper profiles
• Document your workflow regularly
• Use the right color spaces for the right job
• Observe the art in your work

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Valuable CM Resources

• Making fine prints in your digital darkroom,
  Norman Koren
• http//www.normankoren.com/makingfineprints.html
• Andrew Rodneys Digital Dog
• http//www.digitaldog.net/
• CreativePro Books
• http//www.creativepro.com/eservices/bookstore/
• Cambridge in Color
• http//www.cambridgeincolour.com/tutorials/color-m
  anagement1.htm
• Adobe CM Terminology
• http//kb.adobe.com/selfservice/viewContent.do?ext
  ernalId320624sliceId2
• Martin Evening Books
• http//kb.adobe.com/selfservice/viewContent.do?ext
  ernalId320624sliceId2