Colour Management: Determining Quality
Determining the quality of a colour management setup is an expert's task, but there are some visible quality factors that you can check in a profile to see if it is any good.
What you need is ChromiX ColorThink or Apple's ColorSync Utility, a tool which can be found inside the Applications/Utilities folder on Mac OS X systems. Unfortunately, Windows does not have such a free tool that comes with the OS.
Example: A Comparison Between PrintFIX Pro and Eye-One Pro
A visual check of a profile consists in looking at the profile's gamut and colour distribution. A 3D representation of the profile's colour space or gamut is best for examining profile quality visually. Below is a screenshot of a profile created for Hahnemühle Smooth Fine Art Paper using the ColorVision PrintFIX Pro with the highest number of patches. Each patch has to be measured individually with this entry-level device.
To be quite honest, this paper type is one of the difficult ones to create a profile for. It absorbs ink in such a manner that little colour is reflected.
As you can see, the profile's 3D representation contains a lot of irregularities, spikes and holes. This is a bad profile, and if you try to print an image with it, you will very soon run into troubles with colours being out-of-gamut. If you apply the profile to a print job, the driver uses the profile information to determine how the colours will look on the paper. I tested this using this profile, and every image I tried came out as if I applied a posterisation filter to it.
In contrast, I created a profile for the same paper, using a standard TC9.18 RGB test target using the GretagMacbeth Eye-One Pro iO, and this profile does bring out the full gamut of the paper and printer combination. The profile looks like this:
This profile looks smooth, without any spikes or holes. The images printed through it, all look fine. Further examination of this profile, by testing it against the reference file for the test target showed the difference between the expected colour value and the actual colour value for any given Lab value, was not higher than a deltaE (2000) of 3.
This is good, although not exceptionally good. If I were to print the test target and measure it on various moments in time again, and average all those results, the profile would increasingly get closer to the reference values. This, however, is rarely needed with inkjet printer profiles.
The Quality of the X-Rite ColorMunki Design or Photo
In April 2008, X-Rite and its subsidiary Pantone released a new spectrophotometer, the ColorMunki. The ColorMunki is available in two versions: one specifically tailored to designers and one to photographers. The measuring device is identical, only the software differs. On IT Enquirer, I published a thorough review of the Colormunki Design version. In this review, the ColorMunki device and the measuring concept --a very simple approach when compared to the Eye-One Pro concept-- was discussed. For approximately the same price as the PrintFIX Pro, the ColorMunki system is capable of creating the same high-quality profiles as the Eye-One Pro.
The only difference between these devices is versatility, flexibility and smaller tolerances for the Eye-One pro than for the ColorMunki. But where the PrintFIX Pro is almost a toy, the ColorMunki is a professional tool for non-professional colour management users, i.e. designers and photographers who want to focus on the creative part of their job instead of on the technological part of it.
Softproof Certification Key to Colour Profile Quality Assessment
Ugra, the Swiss Center of Competence for Media and Printing Technology, released a tool that checks your monitor's calibration and uniformity. At the end of the tests, you get a report that says whether your monitor is certified for softproofing or not. Few monitors are up to the Ugra's stringent requirements.
U-DACT (Ugra's Display Analysis and Certification Tool) as the tool is called, checks for Grey Balance and monitor stability. It also checks for profile quality. Failing one of the three tests leads to a monitor that gets downgraded to "suitable for creative work only". An U-DACT certified monitor will enable you to assess profile quality and use your printer or proofer profile to soft proof images and color jobs on-screen.
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Ugra recommends that you first of all set up your environment lighting conditions to an optimum state. Then you should calibrate your monitor to a white point of 5000K to 6000K, with a luminance of at least 120 cd/square meter, and a gradation curve of 1.8 gamma. Doing so will guarantee that you have the minimum conditions under which you can start soft proofing. However, these conditions are far from enough. U-DACT normally comes on a USB stick that acts as a dongle as well. The software offers you a startup screen where you select your measurement device. This can be an Eye-One Display, a Sequel colorimeter, a Spyder2Pro, or a MonacoOptix XR2 (DTP94-LCD, as it is called here).
The next tab is the Calibration Check tab. The tab enables you to calibrate your colorimeter, then measure colour patches in the centre of the screen. As soon as the measurements have all been done, the software becomes available again. The next tab lets you measure the monitor's uniformity. For this, you will have to place your colorimeter on white patches in six different areas of the screen. U-DACT supports two monitors. The software will be launched sort of double up. Quitting U-DACT with two monitors attached to your computer requires two Exits (or Quits).
The Summary screen shows you three sliders, which represent a rough estimate of what has been measured. The true value of U-DACT lies in the PDF report that you can generate. This report shows you in detail how different your monitor is from the standard Ugra lives by. If a monitor can be randomly improved by profiling it, it is unstable. I asked Ugra's CEO whether a lot of monitors certify. The answer was "not a lot". Only about 20 models will certify, but Ugra hasn't finished testing all the monitors on the market yet.