Colour Management - Research Questions

What is the purpose of colour management?
(http://www.normankoren.com/color_management.html)


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.
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What problem makes colour management necessary?
(http://www.luminous-landscape.com/tutorials/whats-the-problem.shtml)

Different device types tend to possess different color characteristics and capabilities. Displays, for instance, can't show the same set of colors that a printer can reproduce. This is because of the fundamentally different processes each device uses to produce color content. Scanners and cameras have different color characteristics as well. Even different programs sometimes interpret and process colors differently. Without a consistent color management system, the same picture can look different on each of these devices. The appearance of color content also depends upon the viewing conditions (such as ambient lighting). This is because the human eye adapts differently to different conditions, even when viewing the same picture.

As a result, color management maintains the relationships within color content so that an acceptable appearance can be achieved on devices with different color capabilities and across different viewing conditions. This requires color management systems to control the relationships between the device characteristics and the viewing conditions to produce acceptable results.

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What are the components of a device profile (i.e. what information do the contain)?
(http://www.adobepress.com/articles/article.asp?p=1315593&seqNum=2)

• A colour reference space - sometimes called a profile connection space ( typically CIE Lab)
• A colour profile - to describe the colour characteristics of each device, and the colour gamuts of working spaces
• A colour matching method - to covert colours from one colour space to another using a specified rendering intent (e.g ACE - Adobe Colour Engine software)

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What is the difference between a device profile and a working space?
(http://en.wikipedia.org/wiki/Color_management) and/or
(http://www.adobepress.com/articles/article.asp?p=1315593&seqNum=2)

• The working space that you set in the Edit > Color Settings dialog is the default color space you set in Photoshop. If you start a new document or open a document that doesn't have a profile, the working space is the profile that will be associated with the image. It also means that if you're always opening images that already contain the right profile, the working space never comes into play. You'll notice that there are four working spaces in the Color Settings dialog—that's because each color mode gets its own default. RGB has its own working space, CMYK has its own, and so on. When picking an RGB working space, it's usually best to choose one that's built into Photoshop; for more information see "About the Built-In RGB Working Spaces" later in this chapter.
• The document color space is just another way of saying "the profile that's embedded inside an image." If there is no profile embedded in an image, you can either let your Photoshop default working space take over, manually assign a profile to it, or tell Photoshop to leave it untagged (that is, don't color-manage the document). Photoshop handles document profiles very intelligently: If you have five documents open and each has its own correct but very different profile, there won't be any need to apply the working space to any of them, and in addition, Photoshop will maintain each document's profile separately. Photoshop won't let one document's profile affect another document.
• A device color space represents the range of color produced by a device you use to create or output images. On the creation side, it could be a digital camera or scanner. On the output side, it could be a printer. As we've discussed, device color spaces are valuable for precisely describing the colors of the device that an image came from or is going to, but they are not good for editing, so you'll typically run into device color spaces (device profiles) when you first create or finally output an image.

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What is a 'reference colour space' and  how are they used? Give an example of one.
(http://www.cambridgeincolour.com/tutorials/color-space.htm)

A reference colour space aims to describe all colours visible to the human eye. These RGB values result in consistent colour being produced. They are used as a guide as to which colour space you are working within, giving a standard of colour to compare to. CIE XYZ colour system or CIE L*a*b colour system are examples of systems within the reference colour space.

Whats the difference between 'calibrating' and 'profiling' ?

(http://www.adorama.com/alc/article/8525)

Calibration is the process of making adjustment to your hardware to produce an accurate colour output. Profiling is the creation of a special software file called an ICC profile that precisely describes the output characteristics of your device. Profiling is the result of calibration, the calibration gives you the information needed to create you profiles.

What is a Rendering intent?
(http://www.cambridgeincolour.com/tutorials/color-space-conversion.htm)

Rendering intent allows you to see if the colour gamut you are trying to print at is the same colour gamut that your printer has or if the colours you have in your projected image will be clipped when they come to print. 

Which Rendering intents are most useful to photographers, and when would you use each of them?
(http://www.normankoren.com/color_management.html)

There are two different rendering intents thats most useful to photographers, they are:
Relative colorimetric - this checks colours within gamut and clips out of gamut colours to the closest available colour.
Absolute colourmetric - simulates the output of the printer
Both would be used before printing to give a more accurate idea of which (if any) colours cannot be printed and will be clipped. The most useful one is relative colour metric this allows you to get more accurate vision of exactly what colours are going to be clipped before printing. You can adjust these colours accordingly to suit your image.