> Gerhard, > > This is a very good explaination > of the factors involved. > > Could someone with a colorimeter > create a profile for a specific > camera allowing it to be used for > this purpose?
Kent, Actually you need *all three* items, the camera (which you want to use as measuring instrument), the monitor (which you want to measure) and the monitor colorimeter, in order to create the desired profile. The basic idea is to display color patches with well known monitor RGB values on the monitor and measure their XYZ values with the colorimeter. Additionally you use the camera to take a photo of these color patches on the monitor to obtain the camera RGB values for the patches (with all automatic controls turned off, using well defined manual camera settings). >From these measurements you can now create 1) the monitor profile which establishes the mapping between monitor RGB values and XYZ values and 2) the camera profile which maps between the captured camera RGB values and the XYZ values. As you see (and as I mentioned in my previous mail), actually the camera is *superfluous* in this procedure, if your only desire is to obtain the monitor profile. So what we're discussing here is probably more theoretic than of practical use. Subsequent measurements (of course with limited accuracy) of *THIS* monitor could however now be performed with *THIS* camera, by applying the camera profile to the captured camera RGB values in order to obtain the XYZ values of the patches. Please notice again, the camera profile created in (2) is basically not valid for measuring any arbitrary monitor, but only for measuring *THIS* monitor (or a monitor which uses the same set of phosphors with the same spectral power distributions) with *THIS* camera. (And there are even more factors I haven't mentioned yet, which don't make life easier and reduce accuracy ...) Gerhard -- COMPUTERBILD 15/03: Premium-e-mail-Dienste im Test -------------------------------------------------- 1. GMX TopMail - Platz 1 und Testsieger! 2. GMX ProMail - Platz 2 und Preis-Qualit�tssieger! 3. Arcor - 4. web.de - 5. T-Online - 6. freenet.de - 7. daybyday - 8. e-Post ------------------------------------------------------- This SF.Net email sponsored by: Free pre-built ASP.NET sites including Data Reports, E-commerce, Portals, and Forums are available now. Download today and enter to win an XBOX or Visual Studio .NET. http://aspnet.click-url.com/go/psa00100003ave/direct;at.aspnet_072303_01/01 _______________________________________________ Lcms-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/lcms-user
