On Sat, Feb 22, 2003 at 03:31:34PM -0800, Daniel Rogers wrote: > I have been researching digital color representation. (I was interested > in perhaps writing those color conversion ops on your todo list). I > have found a potential solution, but I want to run it past everyone in > charge to make sure that I should get started on it. > > Color conversion within and around device dependent colorspaces like > RGB, I have discovered, is a very sticky issue. It is almost pointless, > it seems, to consider writing colorspace conversion ops of any sort of > quality without taking into consideration device dependent variables. > > Essentially, RGB (or CMY) color space doesn't specify a white point or > the cromacity of each color component, so these values have to be either > assumed or acquired from some kind of device specific description file > (e.g. an ICC device profile). > > This prompted me to do a little research to see if anyone else has > solved this problem in a manner that would be compatible with the > project. The lcms is a color management library that could be used to > handle the color space conversions correctly. I belive this is the > best solution to the color conversion problem, and would give us > potential for real color management. > > I think that any other solution would have to be rewritten later, > assuming that colormanagment is a desireable thing (and, by all > accounts, it is). > > What do you think? > Yes. We want to start thinking about color management and gegl some. I have so far been more or less following the spirit of the java2d classes for color spaces, color models, and so on. They have some ICC profile based color space classes and use sRGB or CIE_XYZ as a profile connection space. I thought that java2d was using some parts of a Kodak CMS in its implementation, but I am not completely sure of this. There is also the argyll color management lib based from Graeme Gill to have a look at as well. I am curious what bitdepths these libraries handle for different conversions. Feel free to begin investigating these things. I am not an expert at color management issues, and research along these lines is definately helpful. Calvin
