Re: [Openexr-devel] EXIF meta data attributes in headers

[Lars Borg]

In TIFF and DNG all XMP data is stored in tag 700 in IFD 0.

Tag 700 is a byte-sequence with a specified length.

The contents of tag 700 should be copied in its entirety, exactly as is, to a string in EXR. 

No transcoding of the XMP packet is needed.

Not sure what you mean by quick.

Pseudocode:

• get offset to IFD 0
• search IFD 0 for tag 700
• get length and offset to XMP packet
• Make EXR attribute: "XMP", "string", XMP packet

Lars

From: Thomas Mansencal <address@hidden>
Date: Wednesday, July 17, 2013 9:01 AM
To: Piotr Stanczyk <address@hidden>
Cc: Lars <address@hidden>, "address@hidden" <address@hidden>
Subject: Re: [Openexr-devel] EXIF meta data attributes in headers

Piort: That would be fantastic if you can agree on something that lands in the official specs.

Lars: I there a quick way to copy the XMP data from a DNG file which is binary serialised to the string attribute of an EXR file?

Thomas

Thomas Mansencal | thomasmansencal.com
[  thomasmansencal.blogspot.com  |  github.com/KelSolaar  ]

2013/7/17 Piotr Stanczyk <address@hidden>

Sounds interesting ... will take a closer look.

- Piotr

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From: openexr-devel-bounces+pstanczyk=address@hidden [openexr-devel-bounces+pstanczyk=address@hidden] on behalf of Lars Borg [address@hidden]
Sent: 17 July 2013 10:22
To: Thomas Mansencal
Cc: address@hidden

Subject: Re: [Openexr-devel] EXIF meta data attributes in headers

Yes, one XMP attribute of type string.

Lars

From: Thomas Mansencal <address@hidden>
Date: Wednesday, July 17, 2013 7:15 AM
To: Lars <address@hidden>
Cc: "address@hidden" <address@hidden>
Subject: Re: [Openexr-devel] EXIF meta data attributes in headers

To be honest with you either way I don't mind, I have no particular preferences. I just feel that being able to embed exif data is important. We are doing that at work but this is not using any standards since they don't exists. 

Regarding XMP how would you do that, serialize / dump everything in an OpenEXR attribute?

Thomas

Thomas Mansencal | thomasmansencal.com
[  thomasmansencal.blogspot.com  |  github.com/KelSolaar  ]

2013/7/17 Lars Borg <address@hidden>

Thomas,

Why not use XMP instead?

XMP includes all of EXIF + Dublin Core ++

Lars

From: Thomas Mansencal <address@hidden>
Date: Tuesday, July 16, 2013 11:47 PM
To: "address@hidden" <address@hidden>
Subject: Re: [Openexr-devel] EXIF meta data attributes in headers

Hi,

I'm resurrecting that thread after 7 years, I basically wanted to know if there has been more discussions about that matter in the recent years.

The fact there is no standard attributes for common camera data prevents a bit the format to be used as a solid input container for photo processing applications or anything relying on EXIF data. For instance if you want to stitch EXR files with PTGui you will have to enter your data manually.

I think it would be really important trying to establishing a standard list of attributes as suggested by Thomas Lock, the exrstdattr already provides a list of them, maybe completing / updating this one?

Cheers,

Thomas

Thomas Mansencal | thomasmansencal.com
[  thomasmansencal.blogspot.com  |  github.com/KelSolaar  ]