[Bf-committers] ASC-CDL test suite compliance

[Julien Enche]

Hi Andrew,

iv and Nuke show you the data unconverted (so you see Log value without any
Log -> RGB conversion) and without gamma correction.
The problem here is that if I change the code to correctly load this
picture, it will fail for every other pictures I've used so far.

I don't know if OIIO and Nuke are fully DPX compliant, I've always compared
the behavior of my code with GraphicsMagick which still seems to be the most
advanced free software on the DPX/Cineon side (more than ImageMagick). And
the question was also raised about ASC CDL handling [1].

So I don't see any easy way to correct this, perhaps it could be useful to
have a compositor node that allow to apply different LUTs on a picture to
correct it ?

Julien

[1] : http://osdir.com/ml/video.graphicsmagick.help/2007-03/msg00006.html


2011/5/17 Andrew Hunter <andrew at aehunter.net>

> Hey Julien,
>
> I can confirm that OpenImagIO's and Nuke's handling match [1]. Please
> note that Nuke PLE watermarks the image.
>
> Cheers,
>
> Andrew
>
> [1] http://imgur.com/oI7WK
>
> On Tue, May 17, 2011 at 1:11 PM, Andrew Hunter <andrew at aehunter.net>
> wrote:
> > Hey Julien,
> >
> > Thanks for your work, but I think I've uncovered further issues with
> > respect to the dpx handeling.
> >
> > Blender is now internally consistent [1] but the reference image
> > (sop_ref_image.102.dpx) is now very different from what I believe it
> > should be [2].
> >
> > For reference, here is a screenshot of how iv (and OpenImageIO) loads
> > the file [3].
> >
> > I will compare how the file loads in Nuke PLE to try and get some
> > consensus on how this should look.
> >
> > I suspect that the inconsistencies we continue to experience
> > (particularly noticeable on the ASC-CDL transform!) have to do with
> > the conversion from log->lin. Perhaps with pynodes to speed along a
> > proof of concept, we can determine if ImBuf and the color management
> > code is to blame.
> >
> > Cheers,
> >
> > Andrew
> >
> > [1] http://imgur.com/CdNZq
> > [2] http://imgur.com/FnnVz
> > [3] http://imgur.com/fGKfV
> >
> > On Mon, May 16, 2011 at 4:13 PM, Julien Enche <julien.enche at gmail.com>
> wrote:
> >> Andrew,
> >>
> >> You were right, that didn't work. I've released a new patch which should
> >> work fine.
> >> Thanks for reporting !
> >>
> >> Julien
> >>
> >> 2011/5/16 Andrew Hunter <andrew at aehunter.net>
> >>
> >>> Hey Julien,
> >>>
> >>> I've compiled a build with your patch attached and I'm still noticing
> >>> that saved files  don't match what is displayed in the viewer.
> >>>
> >>> I've uploaded a .blend to my server [1] and posted an annotated
> screenshot
> >>> [2].
> >>>
> >>> Lets get this figured out :)
> >>>
> >>> [1]
> >>>
> http://files.aehunter.net/Blender/image-load%20difference-with-dpx-patch.blend
> >>> [2] http://i.imgur.com/6Sl8T.png
> >>>
> >>> On Mon, May 16, 2011 at 10:22 AM, Andrew Hunter <andrew at aehunter.net>
> >>> wrote:
> >>> > Hey Julien,
> >>> >
> >>> > That log -> rgb conversion is a whole other architechtural issue, but
> >>> > I'll leave that aside.
> >>> >
> >>> > Could you please test each of the three blend files from my ASC-CDL
> >>> > package and compare the output?
> >>> >
> >>> > Cheers,
> >>> >
> >>> > Andrew
> >>> >
> >>> > On Sat, May 14, 2011 at 11:44 AM, Julien Enche <
> julien.enche at gmail.com>
> >>> wrote:
> >>> >> If you're talking about the image sop_ref_input_image.1920.dpx, I
> get a
> >>> >> very bright picture (see here :
> >>> >> http://imageshack.us/photo/my-images/830/captureblender1.png).
> >>> >> This image is in Log colorspace, my code convert it automatically to
> RGB
> >>> >> so this is an expected result. GraphicsMagick and ImageMagick give
> the
> >>> >> same output (try display -colorspace RGB
> sop_ref_input_image.1920.dpx).
> >>> >>
> >>> >>
> >>> >> Le 14/05/2011 17:31, Troy Sobotka a écrit :
> >>> >>> Just curious Julien, does your new code work with the ASC reference
> >>> image
> >>> >>> tests Andrew posted above?
> >>> >>>
> >>> >>> With respect,
> >>> >>> TJS
> >>> >>> _______________________________________________
> >>> >>> Bf-committers mailing list
> >>> >>> Bf-committers at blender.org
> >>> >>> http://lists.blender.org/mailman/listinfo/bf-committers
> >>> >> _______________________________________________
> >>> >> Bf-committers mailing list
> >>> >> Bf-committers at blender.org
> >>> >> http://lists.blender.org/mailman/listinfo/bf-committers
> >>> >>
> >>> >
> >>> _______________________________________________
> >>> Bf-committers mailing list
> >>> Bf-committers at blender.org
> >>> http://lists.blender.org/mailman/listinfo/bf-committers
> >>>
> >> _______________________________________________
> >> Bf-committers mailing list
> >> Bf-committers at blender.org
> >> http://lists.blender.org/mailman/listinfo/bf-committers
> >>
> >
> _______________________________________________
> Bf-committers mailing list
> Bf-committers at blender.org
> http://lists.blender.org/mailman/listinfo/bf-committers
>