Please see my comments on these tags inline. > yesterday I showed some jpegs from a digital camera to friends. I opened > gqview, a popular image browser under linux, and could see the images > there in wrong colours. I draged them all to CinePaint to view them colour > managed. My X setup loads automatically the vcgt in a monitor profile from > a (minimalistic) hardware database.
> On the other side the decoration looks with vcgt much more neutral. I have > allmost all decorations set to some shade of gray. The appearence is more > balanced. this is exactly the great advantage of a corrected LUT: every application benefits. And as long, as these applications simply assume a defined state (which will most likely be sRGB), it's an elegant way to do it. I think, the main point for the invention was, that MacOS did always hold the profiles for all apps and the OS, so there's no application that will need access to this information except the OS, which applies the calibration data and sets the corresponding profile as the default monitor profile. > Am 15.10.05, 10:11 +1000 schrieb Graeme Gill: >> Marti wrote: >> >> > lcms does currently NOT implement it because it is not on ICC spec. >> > Alas, I'm a bit critical on such practices. Using this kind of stuff will >> > make profiles "active" in the sense they are no longer a characterization >> > of the hardware but a way to set specific configurations. >> >> You're quite right about this. vgct is not the correct approach >> to calibration. What should happen is that the profile should >> contain the desired device response in the outputResponseTag, >> and some separate system should calibrate the hardware to >> make sure it meets the expected response for a given display >> profile. This provides a mechanism to track device drift. >> >> Unfortunately we're stuck with software systems that expect >> the vgct tag to be present (Apple systems won't load the >> profile if the tag is missing), even though it no longer >> captures all the settings of a modern display system, such >> as the monitor controls etc., and is the wrong information >> to store in a profile .... I have to add a very important item: The profiles, created with ProfileMaker, basicccolor display, Monaco, ... do include the vcgt and are not containing valid device characterization if the vcgt is not taken into account. This does mean, that an ICC-lib should support vcgt tags, as they are required to correctly apply the data of these profiles (which are most likely the majority). On the other hand, this does mean, that this information belongs somehow to the profile. I must admit, that it's not right to include the actual calibration data instead of the desired device response. Oh, and becaus of this I would vote for vcgt support in LCMS to support these legacy profiles (and operating systems ;-) Stefan -- Stefan Döhla mailto:[EMAIL PROTECTED] ------------------------------------------------------- This SF.Net email is sponsored by: Power Architecture Resource Center: Free content, downloads, discussions, and more. http://solutions.newsforge.com/ibmarch.tmpl _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
