Metadata-Layout in IMatch 2023 can lead to misinterpretation

[axel.hennig]

There is a new Metadata-Layout in IMatch 2023 (2023.1.6) called 4 IPTC Metadata which contains a Custom Panel called Image.

For a file which has GPS-Lat/Lon and Reverse-Geocoding information for "Created" and "Shown" the Custom Panel "Image" mixes the metadata.

Created and Shown looks as follows:

So Created in USA and Shown in UK (not really possible, just for testing).

The Custom Panel "Image" looks:

The metadata is correct, but I think interpretation can be misleading, because it shows GPS from USA and City, State, Country from UK.

[PandDLong]

The GPS and geo-tags must drive Mario crazy.

As image location is important to me, I have dug into these tags. Unfortunately the evolution of the tags and associated standards over time have created this odd situation.  The following is my understanding:

1. GPS defaults to being the GPS where the image was created  (makes sense as GPS is automatically added by so many devices and is - by definition - the GPS of the device at the time).  

2. The geo-tags (my term for all of the text based location tags) basically default to Location Shown as, historically, there was really only one set of tags (spread across multiple groups) and they were used to describe what is in the image.

3. When the IPTC Extension was created with distinct Location Created and Location Shown, the mapping of the other geo-tags went to Location Shown.    This is how the standards for the composite tags work (which mask the fact that the same information is repeated in multiple tag groups).

All of this to say, it is messy and the Image metadata panel is correct in terms of the composite standards and/or metadata group(s) displayed.   

I agree it is misleading, perhaps the labels for the tags could be changed to be more clear  (however, that would add complexity as it would put the concept of Location Shown and Created front and centre and - my understanding - few people use this distinction and populate both).


Hopefully this was a somewhat useful ramble.

Michael

[axel.hennig]

Hi Michael,

thanks for your post. What you're describing matches my current understanding of this topic (which I got more or less today, so pretty sure not everything is clear).

Just to summarize in my own words that I'm not wrong:

If I include a photo in IMatch without any GPS-Lat/Lon and without geo-tags (your term for Country, City, Location,...) and I apply in the IMatch Map-Panel the target-marker to that image (and write-back metadata), then

Code Select Expand

{File.MD.XMP::exif\GPSLatitude\GPSLatitude\0}
{File.MD.XMP::exif\GPSLongitude\GPSLongitude\0}
{File.MD.XMP::exif\GPSTimeStamp\GPSDateTime\0}
{File.MD.Composite\Exif-GPSPosition\GPSPosition\0}
gets written. The tags

Code Select Expand

{File.MD.XMP::iptcExt\LocationShownGPSLatitude\LocationShownGPSLatitude\0}
{File.MD.XMP::iptcExt\LocationShownGPSLongitude\LocationShownGPSLongitude\0}
don't get written (I think this is not correct).

If I reverse-geocode the image (filling the geo-tags), then

Code Select Expand

{File.MD.XMP::exif\GPSAltitude\GPSAltitude\0}
{File.MD.XMP::exif\GPSAltitudeRef\GPSAltitudeRef\0}
{File.MD.Composite\MWG-Country\Country\0}  ->  plus State, City, Location
{File.MD.XMP::iptcCore\CountryCode\CountryCode\0}
{File.MD.XMP::iptcExt\LocationShownCity\LocationShownCity\0}  ->  plus CountryCode, CountryName,...
{File.MD.XMP::iptcExt\LocationShownGPSLatitude\LocationShownGPSLatitude\0}  ->  now this gets written (also Lon)
gets written (important: LocationShownGPSLatitude gets written now).
And now it get confusing to me. If I apply an image-direction and reverse-geocode that also, then the previously LocationShown goes to LocationCreated and LocationShown gets filles by the image-direction data.

Summary
That means (in my workflow) I would always have to look into LocationShown and LocationCreated. If  LocationCreated is not filled, then LocationShown is where the Camera was when the image was taken. If both are filled, then LocationCreated is where the Camera was.

[Mario]

That means (in my workflow) I would always have to look into LocationShown and LocationCreated. If  LocationCreated is not filled, then LocationShown is where the Camera was when the image was taken. If both are filled, then LocationCreated is where the Camera was.

Yes.

The Image section in "IPTC Metadata" shows a mix of Composite tags for the location and

XMP::exif\GPSLatitude\GPSLatitude
XMP::exif\GPSLongitude\GPSLongitude
XMP::exif\GPSAltitude\GPSAltitude

which refer to the "created" coordinates.
The composite coordinate values change when the location shown is set (which they are supposed to), the EXIF coordinates don't, which is also correct.

This is all "evolved" metadata which creates a lot of fuzziness. And yes, all this and the also partially obscure mapping between different EXIF, legacy IPTC, native GPS and XMP GPS, IPTCExt Location etc. can drive me nuts.

I've decided the following:

I have removed the lat/lon/alt from the IPTC Metadata: Image section.
This means that the location shown there is the "more correct" location. If there is a "location shown", we see that, else the "location created".

Added a new IPTC Location layout which shows Location Created and Location Shown.

Removed the GPS Details layout - it is now superfluous (except maybe for showing if a file has EXIF GPS and not only XMP GPS, but a) who needs that and b) users can always see in the Browser layout or create their own layout from these tags if needed).

This should resolve the potential confusion in the IPTC Metadata: Image section.
Not many users work with "location shown" data, so it's not a really common issue.

[PandDLong]

That means (in my workflow) I would always have to look into LocationShown and LocationCreated. If  LocationCreated is not filled, then LocationShown is where the Camera was when the image was taken. If both are filled, then LocationCreated is where the Camera was.

That all lines up with my understanding. 

To get consistency across my images, I decided to adjust my workflow and run a metadata template such that the IPTC Extension Shown and Created geo-tags are always populated.  They are often the same but I have found it useful to have them both populated. 

After I started doing this, I have found myself more frequently entering a different sub-location in each even without adding a destination GPS/image direction - it just provides a little more information to the image for display/searching purposes.

For GPS I don't use the IPTC Extension tags, I use and access the XMP Exif tags.

I don't share my images professionally, so I have freedom to setup my own "standards" to simplify my life.  However, I always try to stay within the industry standards to future proof my metadata and keep my options open.

Michael