Hi Lars,

CCIng back the mailing list that got lost.

exiftool can extract them using the following parameters:

*exiftool -xmp -b _MG7890.dng*
*
*
However I ran into something very annoying: Basically when I convert a CR2
file into DNG using Adobe DNG Converter, the essential exif data is not
propagated to the embeded XMP data which is not the case when using Bridge
/ Camera Raw with the generated sidecar XMP.

Here are some various XMP data generated by different process:

- Conversion of a CR2 file with Adobe DNG Converter:
https://gist.github.com/KelSolaar/6027430
See how there is nothing related to camera data? Exposure, focal length,
etc...

- XMP Sidecar generated by Bridge / Camera Raw:
https://gist.github.com/KelSolaar/6027420
Now we have the relevant exif attributes.

- Dng editing in Bridge / Camera Raw:
https://gist.github.com/KelSolaar/6027452
A lot of development data but no exif relevant data.

So question is: Is there a way to easily propagate / convert the exif data
to xmp.

The ideal workflow if Open Exr was to use XMP as I "see" it would be
something like that: Given a CR2 / DNG file, a command line tool ( Like
exiftool ) could be run to create / update the Open EXR file XMP attribute
with the data from the source files BUT this data would need to include the
relevant EXIF tags.

Thomas

*
*




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


2013/7/18 Lars Borg <[email protected]>

> There might be a libtiff tool that can extract or print a selected tag
> (700 or XMP) from a TIFF file.
> Worth trying. Could you look for that?
>
> Lars
>
>
> From: Thomas Mansencal <[email protected]>
> Date: Wednesday, July 17, 2013 9:16 PM
> To: Lars <[email protected]>
>
> Subject: Re: [Openexr-devel] EXIF meta data attributes in headers
>
> Hi Lars,
>
> Thanks for the details.
>
> By quick I was thinking like using a Python script or something like that:
> extracting the data with Python and copying it to the exr with exrstdattr
> using the -string flag.
>
> Thomas
>
> *Thomas Mansencal | thomasmansencal.com
> *[  *thomasmansencal.blogspot.com*  |  *github.com/KelSolaar*  ]
>
>
> 2013/7/18 Lars Borg <[email protected]>
>
>> 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 <[email protected]>
>> Date: Wednesday, July 17, 2013 9:01 AM
>> To: Piotr Stanczyk <[email protected]>
>> Cc: Lars <[email protected]>, "[email protected]" <
>> [email protected]>
>>
>> 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 <[email protected]>
>>
>>> Sounds interesting ... will take a closer look.
>>>
>>> - Piotr
>>> ------------------------------
>>> *From:* 
>>> [email protected][openexr-devel-bounces+pstanczyk=
>>> [email protected]] on behalf of Lars Borg [[email protected]]
>>> *Sent:* 17 July 2013 10:22
>>> *To:* Thomas Mansencal
>>> *Cc:* [email protected]
>>>
>>> *Subject:* Re: [Openexr-devel] EXIF meta data attributes in headers
>>>
>>> Yes, one XMP attribute of type string.
>>>
>>> Lars
>>>
>>>
>>> From: Thomas Mansencal <[email protected]>
>>> Date: Wednesday, July 17, 2013 7:15 AM
>>> To: Lars <[email protected]>
>>> Cc: "[email protected]" <[email protected]>
>>> 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 <[email protected]>
>>>
>>>> Thomas,
>>>>
>>>> Why not use XMP instead?
>>>> XMP includes all of EXIF + Dublin Core ++
>>>>
>>>> Lars
>>>>
>>>> From: Thomas Mansencal <[email protected]>
>>>> Date: Tuesday, July 16, 2013 11:47 PM
>>>> To: "[email protected]" <[email protected]>
>>>> 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*  ]
>>>>
>>>>
>>>
>>
>
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