Introduction to Colour Management

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Introduction toColour Management
DOHMDigitisation of Heritage Materials
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The same image displayed on three different,
uncalibrated systems
Colour is always device dependent!!!
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Human Vision - Colour
SAME COLOUR!!!
Dot colour 1
Dot colour 2
http//www.purveslab.net/main/
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Human Vision - Brightness
Grey and White
SAME SHADE OF GREY!!!
http//www.purveslab.net/main/
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Human Vision - Contrast
THE SQUARES ARE GREY!!!
http//www.purveslab.net/main/
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Concept of White Light
White light is composed of all visible colours
White light components
White light
Prism
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Human Eye Spectral Sensitivity
There are three types of colour
sensitivephoto-receptors (cones) in the human
eye. They are mostly sensitive to blue, green
and red spectrum of light.
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Light sources
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RGB - Red, Green, Blue
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Computer Monitors Magnified
LCD monitor
CRT monitor
1 pixel
Colour perception by the eye
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CMYKCyan, Magenta, Yellow, blacK
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CMYK print
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Colour spaces and gamut
GAMUT - range of colours that a colour system
can display, capture or print
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ICC profilesHow they work
(colours converted from the special universal
standard space into output device colour space)
Profile attached to image
Monitor
STANDARD COLOUR SPACE
Profiles used to correct output colours
(colours converted from capture device colours
into the special universal standard space
colours)
Original Image
Printer
ICC colour profile - information about how
digital devices subjectively see colours
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Colour Management basics

• Calibrate monitor
• Calibrate input devices (scanners cameras if
  applicable)
• Calibrate output devices (printers)

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Professional colour calibration
Special software and hardware is used to
calibrate devices and ensure correct colour
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Practical Colour Management

• Calibrate the monitor using an appropriate
  device(eg. Spyder Express, GretagMacbeth).
  Follow the prescribed procedure carefully.
• Check in computers DISPLAY PROPERTIES gt
  ADVANCED gt COLOR MANAGEMENT that the created
  profile has been installed and is selected as
  default. If not, install it manually.
• When you view images or want to print them out,
  make sure that you open them in software that
  uses ICC colour management (eg. Adobe Photoshop,
  Photoshop Elements, FastStone) , and colour
  management is switched on.

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Benefits of system calibration

• Consistent colour - print matches the original
• Reduced time to obtain good colour results
• Images look the same on different computer
  systems and monitors
• Much better chance of reproducing accurate
  colours in the future (better archival properties)

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QPCard 201
http//www.qpcard.se
How to use it? Go to http//www.qpcard.se and
watch the instructional video
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Colour links

• International Color Consortium (ICC)
  www.color.org
• ColorVision - http//www.colorvision.com/learn_col
  ormanagement1.php
• Microsoft - http//www.microsoft.com/whdc/device/d
  isplay/color/default.mspx

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Andrew Stawowczyk Long email info_at_dohm.com
.auPhone 61 408 478 522 Skype
andrewstawowczyklong