Reviews / COLOR PROFILE
Color profile – is a basis of modern system of managing color.
In simple words, color profile – is a file, which contains information about the device that will convey color. It can be printer, scanner, monitor, projector, and anything else you can use to display color from computer.
Usually, when mentioning a profile, it is meant to mean a color profile, which format was approved by an International Color Consortium (ICC). That is where the name of ICC profile came from. This standard is established by such companies as: Agfa-Gevaert, Adobe Systems Inc, N.V., Eastmen Kodak Company, Apple Computer Inc, Sun Microsystems Inc, FOGRA (Honorary), Microsoft Corporation, Silicon Graphics Inc,, Taligent Inc. Main goal of creating a standard is a system description of color settings of a device. And an object of standardization was reached. Nowadays, almost every company, that is connected with devices , intended to work with color, are a part of ICC standard: Canon, Barco, DuPont, Fuji, , Intel Xerox, Hewlett Packard, NEC, Sony, Pantone, Seiko Epson, Kodak, HP, X-Rite, Gretag and other.
ICC Association has it’s own domain, where anyone can find a needed specification of a standard, developed by consortium, and any other information, for example, initial texts of programs in a C language, which allow to “disassemble” files and get information contained in them in a more easily accessible form.
ICC standard is not attached to any platform. For example, a file created by Apple, can be easily used by Windows. Everything, that is needed for it – adding an icc or icm resolution to the file’s name. A return transfer - from Windows to Apple - is much harder. It is certainly known for Macintosh users, that information about a file is located separately from the file itself (in contrast to Windows, where a type of a file is identified by it’s resolution). If a file is rewritten from Windows, there is no information about it and operating system does not perceive this file as an ICC-profile.
TYPES OF PROFILES
There are three basic types: profile of a data input device (scanner), profile of a monitor and output device (printer). Each type describes how a given device transforms colors from a device-independent color space (Lab or XYZ) in it’s own color space (e.g. RGB and CMYK) and backwards.
A LITTLE PRACTISE
For us, a practical task is of main importance: how to create a combination of ink and halftone algorithm for an ink-jet printer, which minimize color shift on a print, taking on account different lighting (sunny, cloudy, fluorescent, filament bulb etc.). Let’s look at an example (Pic. 1), on which there is shown a difference between initial file and printed photographs on different initial material.
Pic. 1 – initial photograph, original cartridge, CISS
“But how is that? – you may ask, - for original expenditure material we pay colossal money, Gods of ink-jet printing provide it, who just cannot get it wrong… Another thing – CISS, unknown who did a placing on the printer and very suspicious contents, which, as many people think, cannot even called ink.
Both opinions are wrong and that is why. In the first case, even though companies-manufacturers of devices for ink-jet printing and consumable supplies made progress in this area, they have a stream manufacture and are unable to adjust every emitted device. Solution of this problem consisted in using average magnitude on a special apparatus. It is possible, that average magnitude can fit it, but not in printing, where it is not likable to look at an average complexion. Regarding the second variant, where CISS is used, it is still likely, because manufacturers of CISS and ink are doing their best in reaching the quality of printing that will satisfy user.
But what is left to do when neither average nor maximum approximate variants don’t satisfy us and we desire to get photographs which will give out the colors right and have perfect color rendition.
In this case, profiling will help. Profiling is a process of creating a color profile (file with a CISS expansion), considering printing features (ink, paper, lighting etc.) and technical characteristics of a device itself. (Pic. 2)
Pic. 2 – Initial photograph, original cartridge, CISS.
CREATING OF AN ICC PROFILE
It is a hard and laborious process, when we consequently receive an ICC profile, auxiliary and necessary file for a driver of a printer, which contains information on how much and which ink colors have to be mixed (pour out on paper from nozzles of printing ends), to reach maximal quality and color rendition, to get a right color on paper, black must be black, yellow – yellow, and red – red in a strict correspondence and definite demands, regulated by special standards. Tuning of printing is taken through the tuning of color. It allows to make printing of maximal qualitative. Color managing allows to reach high quality of printing.
It is important to understand that color profiling is a significant part of your work, which the quality of your production is dependent on.
Later on here will be a detailed article with examples of creating profiles in different programs.
© 2012 Advanced