[argyllcms] Re: help with camera profile

  • From: Alberto Ferrante <alberto.ferrante@xxxxxxxxxx>
  • To: "argyllcms@xxxxxxxxxxxxx" <argyllcms@xxxxxxxxxxxxx>
  • Date: Sun, 29 Jul 2012 21:05:05 +0200

I get your point, but, as mentioned by somebody else, it is a known fact
that Ufraw does not have a linear behavior. A matrix only profile also
works, but it has a quite high error:
Profile check complete, peak err = 24.309501, avg err = 2.066699

By removing the "usual" L15 patch the error gets below 15:
Profile check complete, peak err = 14.290793, avg err = 1.972512

I have to admit that also the matrix-only profile works quite well with
the new settings: it gives extremely similar results to the single
shaper one. I probably overlooked it when doing the latest tests.

If I try to do the same with the 7D profile, the error gets higher (27
as peak) and even after removing 3 patches it stays to 17. The "bad"
patches are always orange/yellow.

About all the other replies: of course I am aware that a correct profile
may not be visually good. I use proper curves and saturation in ufraw to
give the pictures a look that I like (quite neutral, actually, for
standard pictures... Then this may change down the other phases of


Iliah Borg wrote:
> I see - but that implies you are fighting non-linearity somewhere, probably 
> in 
> the raw converter itself; or your exposures are on the hot side, and you 
> suffer 
> sensor highlight non-linearity?

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