Re: [CinePaint] Working with RAW data
Bob Friesenhahn <[email protected]>
| Newsgroups | gmane.comp.video.cinepaint.user |
|---|---|
| Message-ID | <[email protected]> |
On Sun, 23 Mar 2008, Frank Peters wrote: > > The whole issue can be quite complex but I refer anyone interested > to check out this somewhat convoluted thread on the UFRAW forum: > > http://sourceforge.net/forum/forum.php?thread_id=1907019&forum_id=434060 The phrase "the whole issue can be quite complex" implies that there is some sort of science detailed in this conversation thread which goes beyond "works for me". It seems best to simply admit that using ICC profiles in this way is a "works for me" type situation. While CCD and CMOS sensors are fairly simple and easy to characterize, as used in consumer digital cameras, there is firmware added which may make changes to the biasing of the sensor before the shot is taken, as well as adjust the iris and shutter duration. The sensed colors have quite a lot to do with the colors surrounding the object and the overall color temperature of the scene. The zoom level of the lense has some impact on the appearance of colors. The camera is likely to exhibit a degree of metamerism. The Bayer pattern does not help since it invents colors and sensor sites which do not actually exist. There are a large number of variables which are unlikely to be nomalized by a gross "white balance" adjustment done by software like 'dcraw'. Bob ====================================== Bob Friesenhahn [email protected], http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/