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Scanner CAlibration ReaSonably Easy

Call for developers/testers!

Scarse project is currently under development. Beta-testers and developers are sorely needed. I cannot do everything myself, I have a day job :). If you are interested and want to help, please contact me. My email is all over this pages.


10/20/2005: Scarse version 0.4-alpha is out! This is the first new release of Scarse Project in a while, and hopefully worth the wait. Profile generation algorithm has been almost completely rewritten, and is significantly more accurate and robust. New profile library is drop-in compatible (and tested) with Photoshop/Adobe ACE. The source code has been ported to Windows, and binary Windows distribution is available.

If you are using (or planning on using) Scarse, you should subscribe to scarce-announce mailing list so that you don't miss important bugfixes and new releases. Older announcements from the list, release notes, major bug reports, and even some development rumors all clumped together can be found on this page.

Site Index

What is it?

Scarse is a free color calibration and management software package. It lets you build and use ICC profiles. Custom profiles can be generated from variety of calibration targets. Scarse is intended for (and developed on) Unix machines and is distributed under the terms of GNU Public License.

Scarse project was born out of my desire to be able to get good scans which are consistent across large batches, and do it with minimal amount of manual tweaking. It is intended for serious photographic or prepress applications, and is most useful with high-end film scanners. If you just want to occasionally scan a snapshot of your aunt on your $100 flatbed and don't care about the colors as long as they are snappy, don't bother, this package is not for you.

As the name implies, color management issues are rarely addressed in the free software world, probably because until now good scanner hardware was unaffordable to a mere mortal. With all professional graphic solutions being firmly locked into Mac or Windows platforms, there was hardly anything at all for Unix. However, time marches on, desktop scanners and printers got much better and cheaper, some brave people wrote Gimp, and a color management system for Unix was needed. So I set out to write it...

Right now, the Scarse is in early development stages, and is not as polished as commercial systems are. Indeed, it is quite rough and even downright inconvenient in places. However, it is quite functional already, and produces transparency scans which are superior to what I get from OEM Polaroid SprintScan 4000 profiles (using the same hardware). So if you are adventurous type, give it a try, and tell me what you think...

How does it work?

It works quite well, thank you :). Oh, you meant technical details :)?

Scarse works by comparing the scan of a hardcopy reference calibration target (such as IT8.7 or Kodak Q60) coming from your hardware to the actual colors the target is supposed to have. It then builds (by approximation and interpolation) lookup tables that take into account the measured scanner hardware peculiarities. Using thus generated profile, you can then get scans with color rendition (more or less :) independent of the particular hardware used.

You will need a supported hardcopy calibration target. Standard IT8.7 targets are made by most major film manufacturers for the purpose of calibrating scanners for their films. They offer a lot of color points to measure and thus produce quite precise profiles. Q60 target is available from Kodak in 35mm and 4x5 transparency, as well as 5x7 reflective formats. Wolf Faust makes high quality reflective and transmissive IT8.7 targets and sells them quite cheaply. Other standard calibration targets, such as MacBeth Color Checker and Kodak Color Separation Guide Q13 & Q14 (grayscale only), are also supported.

You cannot calibrate scanner for negative film the same way you can do it with slides, because of the variations in negatives on per-exposure basis. Scarse provides automatic color adjustment which will normalize scan of a negative to roughly correct levels and contrast, and you can work from there. Printing negatives is more of a subjective thing, and some decisions are better left to a human.

As far as results go, see for yourself, and form an opinion.

Who is responsible for it?

Scarse was written and is being maintained by me (Andrei Frolov), with help from many other people. As it usually happens, it all started as a solution of particular problem I had. Besides doing theoretical physics research as my day job, I am an avid backpacker and nature photographer, and I wanted to scan a large number of slides from my files. Not satisfied with the services of commercial labs, I decided to do it myself, and do it right. Being a firm believer in freedom of information, I released the resulting code under GPL. But enough about me, let's talk about...

How do I use it?

Where is the documentation, you ask? "I... ugh... sort of... haven't... yet..." the author hides his face behind the camera and exits to the nearest bushes. "You are on your own!" the wind carries to you from the distance...

That having been said :), I started writing some docs. My feeble efforts in that direction, as well as some related documentation from other sources, are indexed here.

How can I help?

Scarse project is still in early development stages, and could use all the help it can get. We need developers, and we need testers even more... If you find a bug, please report it, including description what went wrong and what were you doing at the time. Better yet, fix it yourself and submit a patch :). Improvement suggestions and (constructive) critique are always welcome. If you feel particularly generous, you can also help by donating hardware (especially densitometer or other color measurement devices) or money.

Still reading?

Then go on to digital imaging links...

Andrei Frolov <>
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