ExifTool Forum

ExifTool => Newbies => Topic started by: j on December 26, 2011, 11:22:09 AM

Title: Keywords and Tags
Post by: j on December 26, 2011, 11:22:09 AM
Okay, I've become an ExifTool expert!  Okay, that's an exaggeration, but I can now geotag, read tags, alter times, copy tags from one file to another, set tags, extract and insert embedded images, and even read the ExifTool manual with savoir-faire.

Now I want to work on keywording my images, and I am hoping I can get some advice from the readers of the ExifTool forum.  I believe I know how to insert keywords, I remember seeing documentation on inserting lists.  What I am not sure of is what key words to use or where to put them.

Let's say, just for instance, I have a picture of a christmas tree, a dog, and some people.  So I am thinking that good tags would be "Christmas, Christmas_2011, Christmas_tree, Rover, dog, Bobby, Sally"

Does that make sense?

And where do I put the keywords?  Exif?  ITPC?  XMP?

I've done a certain amount of reading about metadata and key words in general, and it seems that the answer might be to put the same information in multiple places.  Put that seems like a bad idea.

Any insight would be appreciated.
Title: Re: Keywords and Tags
Post by: BogdanH on December 26, 2011, 12:23:34 PM
Hi "j" -you couldn't pick shorter nickname  :)

Quote...Let's say, just for instance, I have a picture of a christmas tree, a dog, and some people.  So I am thinking that good tags would be "Christmas, Christmas_2011, Christmas_tree, Rover, dog, Bobby, Sally"
Keywords I would use:

Christmas -Yes (however, you could save "Christmas" in Xmp:Event instead -it's your decission)
Christmas_2011 -No: It's enough to define keyword (Christmas) once and 2011 is saved in Exif:DateTimeOriginal (or elsewhere) anyway
Christmas_tree -No: See above
tree -Yes
dog -Yes
Bobby, Sally -No: names belong in Xmp:PersonInImage tag

You should put keywords in Xmp area (use Xmp:Subject tag for that purpose). Of course, you can put (the same) metadata in multiple places, but maintaining (synchronizing) such metadata doesn't make fun at all.

Bogdan
Title: Re: Keywords and Tags
Post by: j on December 26, 2011, 07:58:55 PM
(I thought about using h or i as a user name, but the extra effort to move my index finger a whole extra letter didn't seem worth it.  Same for capitalizing.  Just too much work.  ;) )

Okay, maybe I'm more ignorant than I thought regarding keyword tags.  I'm searching for the simplicity on the other side of complexity.  So far I just seem to be battering myself against the learning curve on this side of this side of complexity.  The more I read the worse it gets.

Should I care about ITPC vs. XMP?

When you said, "xmp:event" I sort of veered off the road.   I imagine that I set that with:

exiftool -xmp:event=Christmas file.jpg

for instance.  But how do I know how many xmp:someword tags there are?  Is there a list somewhere?  Same for Xmp:PersonInImage.

And should I do something with -keywords, -comment, or -xmp:description?

Thanks,
j


Title: Re: Keywords and Tags
Post by: Phil Harvey on December 26, 2011, 08:40:38 PM
Bogdan is suggesting using the new IPTC XMP tags (listed here (https://exiftool.org/TagNames/XMP.html#iptcCore)) instead of the old IPTC IIM tags (listed here (https://exiftool.org/TagNames/IPTC.html)).  This is a reasonable suggestion since IPTC is moving to using the newer XMP format instead of the old IIM.

Note that as well as the new XMP tags that IPTC has defined (the "iptcCore" and "iptcExt" tables), the IPTC Core specification also makes use of existing tags in the "photoshop" and "dc" namespaces.  See http://www.iptc.org/IPTC4XMP/ for all of the gory details.

- Phil

Title: Re: Keywords and Tags
Post by: j on December 26, 2011, 10:44:25 PM
Okay, that helps.

Thank you!