On Thursday 16 June 2005 03:57 am, Jan-Peter Homann wrote: > (If a printer-driver supports devicelink-profiles, user could e.g.print > a testimage, apply the coloradjustments, they want, and print later > every job with this coloradjustment) > > Use your imaging application as devicelink-profile editor > ------------ > > Often an ICC-conversion delivers not exactly the result, which users > expect. But with some coloradjustment, it would be nearly perfect. > > A way to solve this: > 1. Link the ICC-profiles together to an devicelink-profile > 2. Transform an IT-8 like testimage with the devicelink-profile > 3. Edit the transformed testimage in your imaging application > 4. Link the edited values with the original IT-8 values to a new > devicelink-profile. > 5. Apply this devicelink-profile instead your normal ICC-transformation. > > Imagine e.g. the next version of gutenprint comes with lcms-support and > some standard-icc profiles. The results for your printer are good, but > not optimal. > The described way is easy to go, without the need to buy a > spectrophotmeter and a profiling software. > > So this technology makes sense for all color-aware users of opensource > applications and not only for graphic arts color geeks.
I am not too sure that just having a profile editor and some canned profiles is enough. I use non-standard archival inks in my printers and in cases like this canned profiles for the printer and standard inks will not be close enough to give a good starting point for the profile editor. In Windows I have been using ProfilePrism. This software uses a scanner as it's "spectrophotometer". Of course we all know that scanners are not particularly good at this. The software is setup to scan both the test printer target and an IT8.7 target at the same time so this allows it to "calibrate" the scanned result. In addition newer versions have an editor that allows users to manipulate profiles. This editor is designed to use an iterative approach to do the modifications to the profile. The editor presents the user with two views of the test image and in the editor the user will adjust one of the images to look like the printout of the test image. After the user thinks the image is corrected the software will generate a new profile with the changes needed to correct it in the direction indicated by the user. Then the test image is printed with the new profile and used to make additional adjustment to the image to fine tune the result. My experience is that the earlier versions of the software did not give particularly good profiles and that it works better with some scanners then it does with others. With the current version and using a scanner it likes (an inexpensive Canon LIDe 20) I am able to get very good printer profiles without even using the profile editor. But it is very nice to have the editor available to make minor adjustments to my profiles if needed. In the long run I am hoping that something like this will become available as an open source project. I believe that argyllcms is setup to do printer profiles but currently needs a spectrophotometer and is not setup to use a scanner. Nor does it have any type of profile editor. And of course it is a command line only tool at this time. CUPS 1.2 beta is now available. This version of CUPS was supposed to be CM aware (I have not tested it). In addition it appears that the GutenPrint project is also looking into what they need to do in this area. We are getting closer to having open source CM aware printing subsystems. So it is becoming important that users have ways to create good printer profiles. I agree with Jan-Peter that most users other than those that are true color geeks will not have a spectrophotometer on hand to be able to create these profiles. Therefore I think that a printer profiling application that was designed to work with a scanner and has a profile editor is a good compromise for those who want more control than just using a canned profile but who can not justify the cost of a spectrophotometer. Hal ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
