Hello, Trying to summarize what as been said so far, correct me if I'm wrong:
- Everybody here seems to like / want EXIF support in Open EXR. - Four methods: [1] Extending the current specification camelCase attributes with new attributes: Looks like to be an easy way for implementation. This is assuming we have a well defined set of attributes / tags. Problem may be that it can take time to construct a list that makes everybody happy. [2] Like above but the OIIO way which is creating custom prefixed attributes derived from the official exif naming convention ( "Exif:Foo" or "IPTC:Foo" ): Should be relatively easy to implement also. [3] Supporting XMP: Doesn't looks like complicated either, have a growing worldwide support but will most likely rely on dependencies in order to serialize / parse the data whereas filling existing attributes would be very easy using exrstdattr for example. Adobe is behind the format and provides a very complete SDK, the format itself is an ISO standard which makes it kind of future proof. http://en.wikipedia.org/wiki/Extensible_Metadata_Platform [4] Extending current specification using either method 1 or 2 and supporting XMP. Best of both world although subject to discrepancies between the attributes and XMP data. - Adding support for ICC profile attribute. Larry's way in OIIO is quite cool actually and very similar to what we are doing at MPC actually. I'm not a huge fan of the current specification set of camelCase attributes because they don't take their name in any other existing specification ( Again correct me if I'm wrong ). XMP way is although very good but serializing the data while being sure you have propagated the needed EXIF data requires a bit of massaging. What do you guys prefer? Any other methods? Thomas *Thomas Mansencal | thomasmansencal.com *[ *thomasmansencal.blogspot.com* | *github.com/KelSolaar* ] 2013/7/19 Brendan Bolles <bren...@fnordware.com> > On Jul 18, 2013, at 5:58 PM, Peter Hillman wrote: > > > What extra info do you get from the ICC profile? > > > > Allowing ICC profiles worries me. Aren't EXRs supposed to store pixel > values in "input scene referred linear-light" encoded with the > chromaticities specified? That means images must be linearised before > storing in an EXR. > > > I think I'll let Lars answer this one. I guess if there's nothing in a > scene referred linear ICC profile that can't be represented by > Chromaticities, then there's no need for an official ICC profile attribute. > > But I'll freely admit that I allow users to write EXR files off-spec. Not > that I really have any control over it - I get pixels from After Effects > and I write those pixels. If a user wants to store Rec709 data in an EXR, > I'm not going to stop them. I know of at least one major studio that does > this. > > > BTW, I'd love for someone to look over my ICC profile to Chromaticity > code. It seems to work pretty well, except for the XYZ.exr sample file. > > https://github.com/fnordware/openexrAE/blob/master/src/FrameSeq_Color.cpp > > > > Brendan > > > _______________________________________________ > Openexr-devel mailing list > Openexr-devel@nongnu.org > https://lists.nongnu.org/mailman/listinfo/openexr-devel >
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