GPS-annotation not applied to buddy-files

leifel · July 24, 2025, 08:59:51 PM

When I apply a category to a master-file (NEF in my case) that same category is automatically also assigned to any buddy-files. This is nice. However, when I apply a GPS-coordinate to the master-file it is not automatically assigned also to the buddy-files. This cause me some problems in my workflow. Is it possible to have IMatch do this?

Mario · July 24, 2025, 09:22:34 PM

Metadata is propagated during write-back. Note the little * and see Metadata in the help system.
Did you perform a write-back? Which GPS coordinates did you propagate? To be safe, propagate only XMP tags.

thrinn · July 24, 2025, 10:22:42 PM

Quote from: leifel on July 24, 2025, 08:59:51 PMWhen I apply a category to a master-file (NEF in my case) that same category is automatically also assigned to any buddy-files

Just to be precise regarding the wording: When you talk about propagating metadata, you are referring to versions, not buddy files. Yes, I may sound picky, but versions and buddy files are two different concepts, serving different purposes. Both are created by setting up File Relation rules, but of different types.

leifel · July 26, 2025, 09:57:41 AM

Quote from: Mario on July 24, 2025, 09:22:34 PMMetadata is propagated during write-back. Note the little * and see Metadata in the help system.
Did you perform a write-back? Which GPS coordinates did you propagate? To be safe, propagate only XMP tags.

I was unaware (forgot) the "propagate during write back" options. When I experiment with it now I am unable to get it right. The GPS-coordinate I am talking about is the one I get when I manually assign a GPS-position with the "Apply the target marker coordinates to all selected files" button in the Map-panel. In the Versioning-tab of "[V] Nikon Versioning" in File Relations-options I have added "-Composite:GPSPosition" with the Advanced Options, but it does not get propagated into the buddy-file when I perform the "Metadata Writeback"-command. I guess it is because "-Composite:GPSPosition" does not represent the GPS-position that is defined by my manual positioning. Which attribute(s) should I use?

Mario · July 26, 2025, 10:13:36 AM

Don't use Composite. Use XMP metadata unless you have very specific reasons. Composite tags are virtual tags ExifTool makes up from a wide range of sources on-the-fly, and writing back a Composite tag can cause changes in many (sometimes unexpected) places. There is logic behind this for command-line use of ExifTool, but not so much for IMatch.

IMatch writes back "through" XMP. It writes XMP, then uses argument files provided by Phil from ExifTool to map from XMP to corresponding native data like EXIF, GPS and IIM3 IPTC as defined by the XMP standard and the late Metadata Working Group. This works very well. If you propagate Composite tags or EXIF tags, it is very likely that what you have propagated will be overwritten when IMatch maps from XMP back to EXIF or GPS.

GPS coordinates and location data are way more complex than users think. Believe me, I've spend weeks working on this and getting it to function well for all users. There are mile-long discussion threads about which GPS coordinates to fill and when...

GPS coordinates are part of a structured XMP IPTC "Location" tag, and they exist in both a "location created" and "location shown" variant. They are also repeatable, which means an image can have multiple instances of "location created" and "location shown", even with different latitude/longitude/altitude. This is how the IPTC has written their standard and I guess they have their reasons.

In the Metadata Panel, you use the "6. IPTC Location" layout to work with GPS coordinates and location shown/created. This layout manages the complex structured IPTC Location tag for you.
Assigning coordinates in the Map Panel or via an IMatch Location fills these tags. Performing reverse geocoding fills the address part of these tags. Writing back XMP IPTC Location propagates the first coordinate pair also into the native EXIF GPS record.

So, don't just propagate some fuzzy Composite GPS tags or EXIF GPS tags, propagate only XMP metadata, including IPTCCore and IPTCExit, and location data, and coordinates, will be propagated correctly. Then write back and see if the results are as you expect them to be. Metadata is insanely complex and expert features like metadata propagation are a good way to shot yourself into your own foot when you don't have extended knowledge about metadata standards and how EXIF, IPTC, GPS and XMP relate to each other.

leifel · July 26, 2025, 11:41:49 AM

Thanks, you put me on track. I tried to propagate with most of the XMP-attributes without success. But checking "EXIF GPS Data *" in the "What to propagate"-list did the work. When I look into the XMP-files that IMatch create I see they contain very few XMP-tags, and none of them are GPS-related. I guess this is the reason.

Mario · July 26, 2025, 12:36:38 PM

There should be hundred or more XMP tags. What do you mean by "XMP files"? Sidecar files? Embedded XMP? How did you "look" at the XMP data?

Show a screen shot of the Metadata Panel with the "6. IPTC Location" layout selected and a file with GPS coordinates. This is what IMatch will store during write-back.

leifel · July 29, 2025, 10:53:34 AM

I mean the XMP file that is written next to the master image file (I guess this is a kind of a so-called sidecar-file). I look at the XMP-data by viewing this file in a text viewer. It contains very few XMP-tags. Another thing I don't understand is that such XMP sidecars don't exist for all images.

In the Metadata Panel I have no "6. IPTC Location" layout.

As far as I remember I have not manipulated this list by any means. But I have used IMatch since 2004 (version 3), so I am not sure.

When I look at the "IPTC (XMP)" layout there are a number of attributes but they are all empty.

How can I get back the default set of metadata layouts?

BTW, I have tried to attach screenshots, but got error message "The message exceeds the maximum allowed length (60000 characters)" regardless how small they were, so I gave up.

Mario · July 29, 2025, 11:34:56 AM

First, start with Metadata for Beginners, which explains about XMP files and if and when they are created.
As defined in the XMP standard, some file formats use embedded XMP (JPG, PNG, GIF, TIFF, PSD, PSB, PDF, ...) and for all other file formats, including RAW, IMatch creates XMP sidecar files.

IMatch does not propagate metadata to Buddy files. It propagates to versions.

GPS and location metadata is complex. These are structured tags, sub-tags of a parent tag.
You can set GPS coordinates for many tags (EXIF, native GPS, XMP) but only the IPTC Location tags are considered by IMatch. These tags are displayed in the Metadata Panel in the Default layout and in the dedicated 6. IPTC Location layout. These tags are filled by the Map Panel and reverse geocoding. When writing back IMatch stores the XMP data in the image (or sidecar file) and maps the coordinates and location data into other metadata formats, depending on what IMatch finds the image.

QuoteIn the Metadata Panel I have no "6. IPTC Location" layout.

How long are you using IMatch? This layout was added for IMatch 2023. Note that only new installations import the default set of metadata layouts, to avoid overwriting user-modified layouts. You can always re-import the standard layouts from "C:\ProgramData\photools.com\IMatch6\Presets\system.immdl".

QuoteBTW, I have tried to attach screenshots, but got error message "The message exceeds the maximum allowed length (60000 characters)" regardless how small they were, so I gave up.

Use the option to attach files below the editor. If you don't see options below the editor, you are using "quick reply" and then you must click on Preview once to get the extra options.