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Location Information

Paul Barrett

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I have been using the map view in Daminion to add GPS locations to my images in the hope that Synology Photo Station would read that information and create Location tags in its app.


It doesn't


After some investigation and trial and error testing I discovered that when I geo tag an image in Daminion and in Photo Station they write identical information to identical fields with one notable exception. Daminion does NOT write the following tag and value which Photo Station uses:


GPS Map Datum WGS-84


This is too technical for me and I would welcome comments on the relevance of this field to Daminion?




- Paul





Further experiments show that if I geo tag in Photo Station then 'read the tags from file' in Daminion, the map in Daminion shows the correct location.


So if I tag all files in Photo Station and then do a block 'read tags' in Daminion they will both be in sync.


So the only remaining question would appear to be why Daminion doesn't write the tag GPS Map Datum WGS-84

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Hi Paul,


You cam try to save this field into a test image using Exiftool and check whether PhotoStation can read it after this "trick" to determine whether the problem is because of this tag.


We don't force writing thiz tag when updating gps info but because all mao providers that we use are based on wgs84 we can add this tag by default.

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Hi Murat


This a very complicated problem with multiple functions using the same information in a variety of ways so I apologise for the length of this reply. I have tried to make it as easy to follow as possible.



I did as you suggested and forced the WGS-84 tag value into the metadata using exiftool.

  1. Photo Station did not recognise the new tag automatically, even after I did a re-index.
  2. However, when I went onto the geotag function in Photo Station, and even though I had done no search in there for the location, their version of the map showed a location marker for an existing location,

So, where was it getting that from?

  1. To try to find out I went back to the source file and purged ALL metadata using Exif Tag Remover.
  2. I then reindexed the file in Photo Station to purge any data held in the app's database.
  3. Then I went back to Daminion used the map function to place its version of the location in the metadata.
  4. Next, I used exiftool to write the WGS-84 tag.
  5. Then I re-indexed Photo Station again.
  6. I went back into the geotag function in Photostation and, once again, while the WGS-84 tag in the metadata had not been picked up, nevertheless Photo Station was still displaying a location marker.

Conclusion: It must be deriving this from the Lat and Long co-ordinates in the metadata. Why it is not also seeing the WGS-84 tag is a mystery. I will put that question to Synology


Murat - your comment about adding the WGS-84 tag to the metadata by default would be a great idea, because if I ever get Synology to act on it it would make life so much easier.


However, as well as writing the tag TO the file it is also vital that Daminion reacts to information coming back the other way. With that in mind I did a quick test:

  1. I deleted all the metadata from the file, went back into Photo Station and added a geotag.
  2. I deliberately chose a location different to the Daminion marker that it already had in its database
  3. The new marker appeared close to the old one
  4. I told Photo Station to merge the new one with the old Daminion one using the new location as the master. It did that.
  5. Then I went back into Daminion and read tags from file.

When I viewed the Daminion map for the image, it still showed the old coordinates. If I am right, this shows that there is some work to do in both directions.

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