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OpenEXR incorrect gamma and missing alpha
Posted: Sun Apr 22, 2012 7:42 am
by harumscarum
here is problem with 32bits OpenEXR image - missing alpha and incorrect gamma on thumbnails and in the viewer
both same files are opened in MP and Bridge
http://dl.dropbox.com/u/2069868/web/night_0001.exr

Re: OpenEXR incorrect gamma and missing alpha
Posted: Sun Apr 22, 2012 2:41 pm
by thibaud
for previews/view mode
just hit ctrl+h (or "view" > "use alpha channel")
ctrl+M (or "view" > "show alpha") is quite handy too...
now that's actually feature richer than Bridge isn't it ?
As for the gamma issue, maybe it has to do with the color profile used here "sRGB IEC61966-2.1 (linear)" ?
for what it's worth Photoshop and Fusion don't seem to interpret the color space and gamma automatically for this file either. (ae and Nuke do though).
Re: OpenEXR incorrect gamma and missing alpha
Posted: Tue Apr 24, 2012 6:34 am
by harumscarum
"use alpha channel" affects only Viewer, but not Thumbnails (rebuild it didnt help)
Photoshop and Bridge view and open this EXR with correct colorspace (maybe because of OpenEXR plugin installed)
Re: OpenEXR incorrect gamma and missing alpha
Posted: Tue Apr 24, 2012 8:15 am
by thibaud
I suppose the use alpha for thumbnail is something I can live with... as the viewer gives more control.
in any case, if additional functionality for how thumbnail uses the alpha was to be implemented IMO this is not something that should be generic or even file format base but rather thumbnail based.
for reference this is how some other app handle that: (format specific context menu on the thumbnail)
.psd thumbnail context menu:
.exr thumbnail context menu (note the "Default transparency" to revert to format specific default because Opaque was choosen):
Photoshop and Bridge view and open this EXR with correct colorspace (maybe because of OpenEXR plugin installed)
you're right Photoshop does display it correctly (I had "proof color" turned on my first test which disabled the gamma correction)
Re: OpenEXR incorrect gamma and missing alpha
Posted: Sat May 05, 2012 5:50 pm
by harumscarum
there is correct gamma in Bridge from CS6 version
Re: OpenEXR incorrect gamma and missing alpha
Posted: Tue May 08, 2012 10:27 am
by thibaud
Yes, it would be great if this gamma issue could be fixed.
Re: OpenEXR incorrect gamma and missing alpha
Posted: Wed May 09, 2012 1:01 pm
by xnview
You would like to view alpha in thumbnail?
Currently i don't know how to get gamma for OpenEXR
You can change default gamma for openEXR (Load settings>OpenExr>Gamma), 2.2 is better
Re: OpenEXR incorrect gamma and missing alpha
Posted: Fri May 17, 2013 2:37 pm
by jho
Hi xnview,
first of all I would appreciate your great work.
I have the same exact problem with the alpha in the thumbnails. My picture has a black alpha channel. Now in the viewer the picture is shown correct but in the thumbnail view I see nothing because the alpha is black.

Re: OpenEXR incorrect gamma and missing alpha
Posted: Mon Jun 03, 2013 3:23 pm
by jho
Can you say if it is being fixed in the upcoming 0.54?
Re: OpenEXR incorrect gamma and missing alpha
Posted: Mon Jul 22, 2013 12:00 pm
by jho
I attached a screenshot where you can see that the thumbnail is not showing the red ball because in the alpha it is black.
Re: OpenEXR incorrect gamma and missing alpha
Posted: Mon Jul 22, 2013 12:08 pm
by xnview
jho wrote:I attached a screenshot where you can see that the thumbnail is not showing the red ball because in the alpha it is black.
could you send me the file?
Re: OpenEXR incorrect gamma and missing alpha
Posted: Mon Jul 22, 2013 12:52 pm
by jho
Hi,
thanks for the fast reply. When I am at home I can sent you the exr file.
Re: OpenEXR incorrect gamma and missing alpha
Posted: Mon Jul 22, 2013 7:38 pm
by jho
I have sent you the image to contact@
<-- removed* --> : Subject is OpenEXR alpha
Re: OpenEXR incorrect gamma and missing alpha
Posted: Wed Nov 13, 2013 2:17 pm
by xnview