ExifTool Forum

General => Metadata => Topic started by: blackbear on November 19, 2010, 09:27:42 PM

Title: Photo Categories embeded in image file
Post by: blackbear on November 19, 2010, 09:27:42 PM
I am looking into the options for tagging my photo collection (1000's of photos).  I would like embed categories (people, event, location, etc) with corresponding tags in each image file.  I know of some programs (using exiftool as a backend) that support something close to this; however, they don't store the categories in the image instead they use an index file which link the tags to the categories.  I am wondering if there are any standards that currently support what I am after.  I am also wondering if EXIF, IPTC or XMP have support for this.  I know I can write my own software to support this; however, I would prefer to use a standard if one exists.

I have already tried: exiftool -People="John Smith, James Smith, Anna Jones" image.jpg and that works.

Any help / thoughts would be appreciated.  Thanks!
Title: Re: Photo Categories embeded in image file
Post by: Phil Harvey on November 19, 2010, 10:00:56 PM
For the categories you mentioned (people, event, location), the XMP IPTCCore and IPTCExt schemas seem to fit well.  You should look at these tags the newer IPTC specification (referenced from the ExifTool XMP tag name documentation (https://exiftool.org/TagNames/XMP.html#iptcCore)).  If possible, it is always best to go with an accepted standard, and IPTC4XMP is a good one to use.

Also, it may help to read FAQ number 17 (https://exiftool.org/faq.html#Q17) to become familiar with writing list-type tags.

- Phil
Title: Re: Photo Categories embeded in image file
Post by: blackbear on November 20, 2010, 07:50:52 PM
Thanks for the pointers.  Do you know if there are any linux GUIs that support them?
Title: Re: Photo Categories embeded in image file
Post by: Phil Harvey on November 20, 2010, 09:25:11 PM
Quote from: blackbear on November 20, 2010, 07:50:52 PM
Do you know if there are any linux GUIs that support them?

I'm not sure, but I think I heard that ImageMagick now has XMP support.  I don't know any other Linux GUI's.

- Phil
Title: Re: Photo Categories embeded in image file
Post by: Storhaug on November 23, 2010, 04:53:42 PM
Quote from: blackbear on November 19, 2010, 09:27:42 PM
I have already tried: exiftool -People="John Smith, James Smith, Anna Jones" image.jpg and that works.

I also started to document the names of the people in photos. I am using:

exiftool -XMP-iptcExt:PersonInImage="John Smith" -XMP-iptcExt:PersonInImage="James Smith" -XMP-iptcExt:PersonInImage="Anna Jones" image.jpg

I have no idea, whether -XMP-iptcExt:PersonInImage is a better choice than -People or not.

Any opinions are welcome.
Title: Re: Photo Categories embeded in image file
Post by: Phil Harvey on November 24, 2010, 07:09:05 AM
Quote from: Storhaug on November 23, 2010, 04:53:42 PM
I have no idea, whether -XMP-iptcExt:PersonInImage is a better choice than -People or not.

The People tag is a proprietary iView Media Pro tag.  The PersonInImage tag is part of the new IPTC specification.  Definitely use the latter.

- Phil
Title: Re: Photo Categories embeded in image file
Post by: blackbear on November 26, 2010, 08:03:11 AM
Is the ModelAge tag meant to correspond with the PersonInImage tag?  For instance: if I add Bob, Larry and Tony to the PersonInImage and then add 3, 7, 2 to the ModelAge will that suggest that Bob is 3, Larry is 7 and Tony is 2?

Thank you for the helpful responses thus far.
Title: Re: Photo Categories embeded in image file
Post by: Phil Harvey on November 26, 2010, 08:30:22 AM
The IPTC4XMP specification (http://iptc.cms.apa.at/std/photometadata/specification/IPTC-PhotoMetadata-201007.pdf) states:

"Age of the human model(s) at the time this image was taken in a model released image. The user should be aware of any legal implications of providing ages for young models. Ages below 18 years should not be included."

Don't shoot me, I'm just the messenger.

- Phil
Title: Re: Photo Categories embeded in image file
Post by: blackbear on November 26, 2010, 04:28:52 PM
So if the PersonInImage are Tony, Tom and Tim where Tony is 35, Tom is 8 and Tim is 29, How do I exclude Tom while appropriately setting the ages for Tony and Tim using the ModelAge tag?
Title: Re: Photo Categories embeded in image file
Post by: BogdanH on November 27, 2010, 03:43:13 AM
Hi,

I assume, that this (as most of IPTCext) values are ment for agencies. And if so, then IPTC should be more precise when describing (recommending) usage of those tags.
In my opinion, tag ModelAge (and other "Model" tags) should be "sub-tag" of PersonInImage. In this case, ModelAge, ModelReleaseID, etc., would belong only to single (root) PersonInImage.

As it is now, one can carefully specify i.e.:
PersonInImage: Tony,Tom,Tim
and corresponding ages:
ModelAge:35,0,29 -where zero means "under 18"(?)

The problem is, that editing those tags can ruin sequence -actually, nobody (except writer) knows which data belongs to each PersonInImage. For now, I'll pass on further comments about IPTC specs  :)

Greetings,
Bogdan