[argyllcms] Re: What to include in bug reports?

  • From: Daniel Bachler <danyx@xxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Tue, 13 Oct 2009 16:25:07 +0200

2009/10/13 Graeme Gill <graeme@xxxxxxxxxxxxx>
> Does this happen when you run dispcal from the command line ?

The crash during profile generation with version 1.1 happens when I
start it from the command line as well (the last lines that are
printed to the screen are:

About to optimise input, matrix and output together
About to adjust a and b output curves for white point
About to create grid position input curves
~1 Doing extra fitting!
~1 Doing extra fitting!
~1 Doing extra fitting!

I followed Nikolay's advice and used version 1.0.4 to create the
profile and this worked (thanks Nikolay!).

The other problem I noticed (several patches displaying repeatedly
while the patch counter goes up, then the patch counter staying the
same and patches changing colour during calibration) is hard to
reproduce. I am not sure if it happened this time again. The
calibration file does not show any two lines with identical values, so
maybe everything works as intended and I was seeing things...

Anyhow, now that the profile generation works (using version 1.0.4), I
have another question: When I take a look at a gradient image in
photoshop that goes through all the colours at full saturation (from
red to green to blue to red again with the secondary colours in
between) in a document that is in prophoto colour space the whole
gradient is pretty uniform and seems to go to the maximum saturation
as expected, except for a stripe around maximum blue saturation. There
it drops off in brightness and saturation and this is by far the most
non-uniform area. In a smaller colour space like adobe rgb everything
is fine. I assume that this is because the prophoto colour space
extends outside the famous horseshoe of visible colours, correct? But
what I find strange is that it doesn't get mapped into the most
saturated blue range but instead to a visibly darker and (maybe) less
saturated area. Is there a way around this issue? Is this an issue of
photoshop? Or is this transformation more complicated that it seems to
a novice in colour transformation like me?

Overall the profile and calibration obtained using argyllcms seam to
be a lot better than those generated by the spyder 3 pro calibration
software. Thanks for making argyllcms :)


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