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6. CONCLUSIONS

This is a rapidly evolving field. Initial provision has been application-based and aimed at the DTP and Print fields. There are many extensively featured packages available, only some of which contain CMS. More are available on Mac than other platforms. However, the operating system extension approach, pioneered by Apple, and being followed by Microsoft and undoubtedly suppliers of UNIX workstations before long, will begin to remove the distinctions between what is possible with different packages.

At present there is still a lack of understanding of CMS amongst some supplier's salesforces. Partly as a result of this lack of expertise, we also found it difficult to obtain technical information in some cases. Sales staff did not understand the questions being asked. We came across a salesperson who thought that problems of colour matching were solvable simply by buying a more expensive printer. Consequently, for those who require a CMS, but are not experts, care must be taken when purchasing a package.

The qualities to look for in a Colour Management System will lie in the colour matching algorithm for out of gamut colours, and the range of profiles provided. A good system will allow the user to expand beyond the basic profiles. This can be achieved by having a very comprehensive list of profiles to cover any conceivable device, or by having a basic system with very few devices of its own but able to accept third party plug-ins. There are professionals who care very deeply about getting as close a colour match as possible. These people will be interested in the toolkits and systems that allow them to create their own profiles. This does allow for very precise tailoring of the system, but the general user will gain more by having a large pool of created profiles to draw on. The ideal system, of course, would cater for both categories.

Nowhere have we come across information about how accurately matches are provided between devices. Without a larger-scale project, and a spectrophotometer or colorimeter, it is not possible to comment further. However, the underlying principles are long established and it is to be expected that major suppliers will have implemented them competently. Gamut matching algorithms could also provide information on the size of error that they produce, but we have found no information on that aspect of performance.

The current generation of CMS provide colorimetric matches, i.e. the assumption is that viewing conditions of, say, monitor and print, will be the same. Unfortunately this may often not be the case. A given colour, i.e. a particular XYZ value, will appear different when viewed on a monitor with a dark background in a dimly lit room to the same XYZ values surrounded by white paper and seen in daylight. In order to cope with changes in viewing conditions appearance matches are required, with compensation for changed viewing conditions. Theory exists to provide this, but there is apparently no use yet made of it in the current generation of CMS. Some CMS literature does make reference to the need to control viewing conditions and the Photoshop monitor setup includes ambient light information.

Nevertheless, colorimetric matching between devices, in an open system manner, will provide a big advance for those for whom the verisimilitude of colour images is important.

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