Image meta-data

Started by domdib, March 21, 2009, 07:34:03 pm

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I was just wondering - because OpenEXR files (and others) allow the storage of meta-data within themselves, and .tgd files are essentially text (XML) - would it be possible to have the option on saving to simply bake the .tgd data into the file? Of course one could do this manually (unless there's an upper bound on meta-data size?)


I have to say that's a very interesting question, I never thought about anything like that.

It could be handy in storage and transport of important projects...


Yes, storage and archiving. My main potential use would probably be re-rendering old projects with higher settings when I get a more powerful machine. I imagine it might come in useful in commercial settings too.


Sounds kind of like an abuse of the EXR format, frankly. I don't know if there's an upper bound on the amount of meta data, but TGD files can get pretty large. It's an interesting concept, but how practical or useful it is I don't know...

- Oshyan


Perhaps it's not an abuse...  I just Googled OpenEXR meta-data, and came across this interesting quote:

"One thing that has been really interesting in the last couple of years has been the OpenEXR format for carrying images - in addition to being a floating point, 16-bit capable format its also an instructionally related format which means that the header is a database about the original material in the picture file.

"If we had an image sequence of OpenEXR frames I could take the original image with the unfilled header information and ship it to you in another country and you can work for three weeks on that image and then instead of sending me back the picture and the header information you send me back the header information only which of course is vastly smaller than the 16-bit picture. I apply that to my original 16-bit picture and it recreates that set of instructions that it receives from the header and I end up with the same picture that you are seeing on your screen."

"The header is instructions and comments about the work done to the picture and the picture itself remains intact you just send me the instructions - here's what I did to  modify this VFX shot etc..."

In any case, I'd just like to register my gratitude that TG2 does output in this wonderfully flexible format.


@domdib -  This might be something to try.  Thanks for the update.  Maybe this could prove really useful.
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Having looked into this a little more, it seems that getting info into and out of the header of an OpenEXR file is a rather technical business: and using the standard metadata of Caption, Comment etc. allowed by Photoshop just won't cut it. So it seems my idea is rather impractical. Too bad. I guess for now I will have to content myself with zipping the .tgd with important files.


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