Metadata parsing from RAW & JPG - What tags to Parse?

[SK]

Hi All,

I am planning to write a GUI to

• scan a given folder and create a database of all the metadata + thumbnails...and
• Display metadata from a thumbnail

Are there any "best practices" as what tags I must parse & store (example EXIF tags, XMP tags, FILE groups, MAKERNOTES, COMPOSITE et all)? Is there a "common denominator" of all tags that most software will recognize?

I do not own lightroom - what tags does lighroom store?

Any suggestion would be appreciated.

Thanks

[StarGeek]

I do not own lightroom - what tags does lighroom store?

I've done some documenting on what tags Lightroom 4.4 writes to here.

[SK]

Hi StarGeek,
Very useful information you have posted. As an example lightroom Copyright is associated with the following tags as per your chart:

• EXIF:Copyright
• IPTC:CopyrightNotice
• XMP:Rights

My understanding is that when you make changes to Copyright info in lightroom, the software updates all the tags that it is associated with? meaning in our example the copyright updates are done on EXIF, IPTC and XMP tags above? Have I understood it right?

[StarGeek]

Yes, that's correct.  When you update the copyright field in Lightroom 4.4 (I don't have access to newer versions), it will write the data to those three fields.

You might also want to look at the Metadata Working Group specs.  The docs on how it's implemented in Exiftool is here and there's a link to their website on that page.

[SK]

Thanks StarGreek! I have noticed that "keyword" is not mentioned in your chart....have you excluded any such tags?

[StarGeek]

 

How the heck did I miss that?  It's not in my notes either.

If I recall, LR wrote keywords to IPTC:Keywords, XMP:Subject, and XMP:HierarchicalSubject.  I'm planning on double checking all that as well as adding more info soon anyway.

[StarGeek]

I hadn't re-installed LR since I had a HD crash at the end of Nov.  I just did so and now see why I missed out on the keywords.  Keywords has its own section separate from the rest of the metadata and I had tunnel vision when I worked on that data.

[SK]

Hi, don't curse yourself so much  After all you have done a wonderful job documenting all the tags!