Re: [Gimp-user] Re: Re: Re: Monitor for Gimp
Hi, David Burren [EMAIL PROTECTED] writes: Does that description clear up anything for you? Yes, that was a very helpful explanation. Thanks a lot. Lack of support for this stuff in the Gimp et. al. is the main reason I moved to Macs (I have an IT background, but these days work as a professional photographer). I haven't given up the Gimp entirely yet, but its getting less and less use over time. Since we have display filter modules in GIMP 2.0 and there's a color proof display filter module already, it's probably less than an hour work to add a display filter that uses lcms to color-correct for the monitor. The only issue with this is that display filters are not yet nicely integrated into the workflow. You have to manually select them for every display you open. This is something that I'd like to see improved for GIMP-2.2. If there was a standard on where to look for the monitor ICC profile and such, that would certainly make things easier. There's a newly created mailing-list on freedesktop.org that deals with this stuff. If you want to join this list, please see http://pdx.freedesktop.org/cgi-bin/mailman/listinfo/openicc Sven ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
Re : [Gimp-user] Re: Re: Re: Monitor for Gimp
Le 31.03.2004 22:29, John Culleton a écrit : On Wednesday 31 March 2004 01:34 pm, GSR - FR wrote: [EMAIL PROTECTED] (2004-03-31 at 2011.13 +0200): [.. destructive compression ..] I am busy window shopping on Ebay etc. If the monitor has an adjustment for color temperature is that the equivalent of adjustable gamma? Or are they different parameters? No, it is an other thing. There are 4 important parameters: - white point and black point, both are adjusted with brightness and contrast settings - colour temperature: a tungstene light has a colour temperature of about 3200K, a flash lamp gives you a colour temperature of about 5500K, sunny daylight is about 6500K. With high colour temperatures, the colour cast is blueish, with low colout temperature, it is redish. Normal office work dispaly uses color temperature as high as 9300K. For photography, 6500K is better. - gamma : this is the non linear function transfer of the brightness given by the display as a function of the pixel value. -- - Jean-Luc -- John Culleton pgp0.pgp Description: PGP signature
Re: [Gimp-user] Re: Re: Re: Monitor for Gimp
On Wednesday 31 March 2004 03:52 pm, Jean-Luc Coulon (f5ibh) wrote: Le 31.03.2004 22:29, John Culleton a écrit : On Wednesday 31 March 2004 01:34 pm, GSR - FR wrote: [EMAIL PROTECTED] (2004-03-31 at 2011.13 +0200): [.. destructive compression ..] I am busy window shopping on Ebay etc. If the monitor has an adjustment for color temperature is that the equivalent of adjustable gamma? Or are they different parameters? No, it is an other thing. There are 4 important parameters: - white point and black point, both are adjusted with brightness and contrast settings - colour temperature: a tungstene light has a colour temperature of about 3200K, a flash lamp gives you a colour temperature of about 5500K, sunny daylight is about 6500K. With high colour temperatures, the colour cast is blueish, with low colout temperature, it is redish. Normal office work dispaly uses color temperature as high as 9300K. For photography, 6500K is better. - gamma : this is the non linear function transfer of the brightness given by the display as a function of the pixel value. So how do I determine which monitors, if any can have adjustable Gamma? BTW I specified 3.0 gamma in my XF86Config file but I can spot no difference in the test files. So my current Orion monitor (17) does not seem to adjust. -- - Jean-Luc -- John Culleton -- John Culleton Able Typesetters and Indexers http://wexfordpress.com ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
Re: [Gimp-user] Re: Re: Re: Monitor for Gimp
Hi, GSR - FR [EMAIL PROTECTED] writes: Let try sorter: the question was do you consider global gamma adjustment useful at all? and the reply was yes, not only useful but a basic. Well, I sortof find it distracting to have the user interface gamma corrected. If I set a reasonable gamma value on my X server, things look washed out and pale. Is that really desirable? Sven ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
Re: [Gimp-user] Re: Re: Re: Monitor for Gimp
Just in case this wasn't clear in my last message, I'll expand on a few points. You can implement either or both of calibration and profiling. Having systems calibrated to a common standard means that you don't _have_ to worry about ICC profiles etc IF ALL YOU'RE DEALING WITH IS RGB DATA IN THE COLOUR SPACE REPRESENTED BY THAT CALIBRATION. Thus with the Gimp in its current form, calibration is important (it's the only thing available!). But if you want _accurate_ colour you need to implement profile support (e.g. building on top of lcms) including dynamic conversion from an image's colour space to the display system's profile. With full profile support it doesn't matter what the user's system is calibrated to (e.g. weirdarse 1.8 gamma). If an image's data is in sRGB the colours will get converted so that what is displayed on the screen is accurate, even though sRGB has a gamma of 2.2. My systems are calibrated to a gamma close to 2.2, and I can view images in ColorMatch RGB (which has a gamma of 1.8) with no problems as the profile conversion takes care of that for me.. Calibration benefits the non-colour-managed applications, but with only limited usefulness. Mac and Windows systems implement both calibration and profiling in an attempt to serve both CM and non-CM applications (and the calibration can help ensure the system is in a reasonable state prior to profiling). Full profile support is important because the colour response of your inkjet printer, scanner, printing press, etc will probably not match that of your calibrated system, and for accurate work you need a profile describing the colour space of each and to convert between them as required. I'll shut up for now. ;) Cheers __ David Burren ___ Gimp-user mailing list [EMAIL PROTECTED] http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-user
