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reliability in digital image production

 

Control tools for handling digital images
To help a photographer estimating what he will get back when providing a printing office whith digital images, it can help to make use of control tools.For that purpose, digital test images and digital control step wedges are highly usefull, as well as standard ICC-profiles for really existing output devices.

Test files with reference prints

„Fine tuning“ between photographer and professional laboratory becomes much easier by using test images which the lab delivers to the photographer by means of digital files as well as paper prints.

By comparing the lab's prints to the color appearance on a particular monitor or self-made inkjet print the photographer can distinguish whether the production chain works properly, or whether he has to adjust his files before sending them to the lab.

A good example for this approach is the so-called DQ-Tool, provided by the German 'Photoindustrieverband'. (Pretty popular in Germany and some other European countries).

By principle, such kind of tools are recommended especially when initializing a color management workflow between photographer and laboratory.


Digital Control Step wedges
An other, very important tool are digital control step wedges. They should be used when building up a 'color communication' between photographer and printing company trying to acheive highest quality with the lowest possible number of test prints. In that case, both partners HAVE to make use of color management techniques.

If the photographer delivers image data, providiing an additional proof print he can describe how the colors should look like on the final large format print. If this target print contains a control step wedge, the lab can evaluate whether this proof has been printed using proper color settings, an whether this print can be regarded as 'proven'. By the way: this kind of quality control is very common in the printing press (and pre-press) industry.

The Photogamut working group is currently developing test images as well as digital control files like step wedges in order to optimize color management workflows especially in the photographic field.

Our dedicated goal is - by that way - to define a common procedure which allows to check and assure the quality of RGB image data and prints. The basic test images and control step wedges will be available free of charge for all photographers and printing services.

This procedure is planned to be proposed for national and international standards.


Standard ICC Profiles
The PhotoGamutRGB profile was designed to incorporate the color spaces acheived by many common combinations of printig devices and papers. Therefore it must be larger than the color space of really existing printing systems. For softproofing purposes, we find it a good idea to use standard profiles of real printers. The soft proof allows a simulation of the final printing result on your monitor providing a very good color matching.