Anybody else unhappy with Red River's R3000 profiles?

Started Mar 23, 2013 | Discussions thread
Hugowolf
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Re: Brian, you win!
In reply to jtoolman, Mar 26, 2013

jtoolman wrote:

Petruska wrote:

Hugowolf wrote:

Have your tried using a perceptual rendering intent instead of relative colorimetric? ICC profiles allow for six lookup tables (LUTs), two for each intent. There should be an input to connection space table, and a connection space to output device table for each intent supported, and even an inexpensive profile builder should support tables for at least perceptual and relative colorimetric.

Brian A

Yes, Perceptual intent produces the correct purple block. There is still something wrong with a lot of the R3000 RR profiles as that purple block soft-proofs blue with Relative and soft-proofs as purple with Perceptual. Other RR profiles, Ex: Paper Canvas, soft-proofs purple for both Relative and Perceptual. All my custom Red River paper profiles made with the Xrite I1PRO or Xrite Pulse system soft-proof as purple with both Relative and Perceptual.

Most users use Relative intent, I don't, I use Perceptual 99.9% of the time as I print mostly portraits and find the out of gamut remapped lighter colors of Perceptual more pleasing. This is why I have never noticed anything wrong with RR supplied profiles when I first got my R3000. My custom profiles eliminate all issues. Relative intent gives more saturated colors, especially with BP Comp. turned off. So I can see where some users may be upset with not being able to use it correctly with some prints. The Epson profiles also soft-proof the purple correctly with Relative or Perceptual. RR has a problem.

Bob P.

Bob, does it matter if one use a specific rendering intent used for printing the test patches during the production of the profile?

Will the user then be "Locked" to the specific Rendering Intent used during the production of that profile when one prints using that same profile?

It shouldn't matter. The patches are produced without color management by the driver and without color management from the software. The media setting, which dictates things like how much ink is put down does matter, but without CM, there is no redering intent used. Without color management, you can't use a rendering intent.

It is up to the profiling software to produce LUTs for each of the three common intents from those patches, either iteratively, as with ColorMunki, or using a much larger number of patches in a single pass with the more expensive alternatives. All three intents, perceptual, colorimetric, and saturation, can be calculated from the unmanaged output. (The difference between relative and absolute colorimetric is only in the position of the white point, so the same table pair is sufficient for both.)

How colorimetric and saturation tables are calculated is relatively simple with little variance between methods, Shifting the gamut within the space for perceptual is much more of a back art, and will vary greatly between implementations.

And it should be noted that there are some obvious differences here between version 2 and version 4 International Color Consortium profiles. You could try reading the specs at icc.org, but like any commitee driven specs, they are as thick as mud. It is probably better to start with someone who has to deal with the fallout of those specs, such as Argyll, if you want a better understanding:
http://argyllcms.com/doc/iccgamutmapping.html

Brian A

Brian A

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