Copying GPS metadata from one image to another

Started by rolandgifford, July 16, 2023, 12:36:42 PM

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rolandgifford

I have recently imported about 30,000 images from a recent trip and have mapped them to a GPX track of the trip. I have previously set my GPS tracking app to not record while stationary so there are regular gaps in the track and consequently several images which have no GPS data, about 4,000. There will be other reasons for misses but I suspect this track gap issue to be the most common.

Question 1 is what should I be copying when doing Ctrl-C/Ctrl-Shift-V? There are 4 GPS related choices, should I be selecting all 4? I could detail what I have done in the past but that probably doesn't help. I am copying from images where the GPS data has been populated by track matching.

I can probably add missing data either by copying or by selecting locations on the map panel but like to see what is there and possibly enter directly in the metadata panel by copying from some other source.

The IPTC Location panel has been suggested to view GPS but in my case this doesn't show the individual values and is sometimes empty for images which have XMP GPS values and hence a world icon on the image. I haven't spotted any pattern for the two to be out of line with each other.

The panel shows like this on my system. I can expend the fields by clicking add followed by delete but there is presumably some setting I have disabled by accident:

Screenshot 2023-07-16 103458.png


Question 2 is how do I make the IPTC Location panel expand by default?

Question 3 is how should I identify images which don't have GPS data? The XMP and IPTC GPS data values aren't synchronized by write-back. Which of them are used for reverse geocoding?

Mario

#1
QuoteQuestion 2 is how do I make the IPTC Location panel expand by default?
You expand the set by clicking one an entry in the list.

QuoteQuestion 3 is how should I identify images which don't have GPS data?
What do you mean by GPS data? Coordinate (lat/lon/alt) or additional location data added by you or reverse geocoding?
Location created or location shown?
How was the GPS data added? By the device? Map Panel? By you manually? By copying coordinates or ...

An image may have a GPS record with lat/lon/alt date and time and some other tags.
Coordinates may appear in Composite tags, EXIF GPS tags (native GPS data) and, mirrored, in XMP exif GPS tags and IPTCExt Location tags. All this depends.

When you add an image with GPS coordinates set by a device, and you look at the metadata in the MD panel using the Browser layout, you see the GPS Coordinates in the Composite section, in the GPS section and again in the XMP exif section. ExifTool mirrors the native GPS data in Composite tags and maps them to their XMP counterparts.

When you switch to the "Default" metadata panel and copy the four tags in the GPS section (Composite tags) and paste them to another file, the Composite tags are copied.

When you now write back, a lot of magic happens behind the curtain, in IMatch and in ExifTool.
The coordinates are written. ExifTool maps them from Composite tags into native GPS tags. When IMatch re-reads the file, it reads the new Composite tags and native GPS tags and makes ExifTool map the n native GPS data into the XMP GPS data and IPTC location created. Also a lot of digests (check sums), time stamps and other tags are created / updated during that process.

What sounds as simple as GPS Data has become quite complicated and somewhat messy, due to the mirrored (but not always) nature of native GPS data, XMP GPS data and IPTC location data (which even exists in two flavors and can have multiple different sets of GPS coordinates and locations for the same image)...
-- Mario
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rolandgifford

Quote from: Mario on July 16, 2023, 01:02:58 PM
QuoteQuestion 3 is how should I identify images which don't have GPS data?
What do you mean by GPS data? Coordinate (lat/lon/alt) or additional location data added by you or reverse geocoding?
Location created or location shown?
How was the GPS data added? By the device? Map Panel? By you manually? By copying coordinates or ...

I mean the 4 GPS tags on the Default layout.

This data has been added by mapping to a GPX track using the map panel. I intend to use it for reverse geocoding.

To add this data to images missing this data I will primarily be using Ctrl-C/Ctrl-Shift-V from images which do have the data. I need to know which of the four GPS options available for paste are the correct ones to achieve the copy without confusing matters by copying too much or contradicting each other.

I may add coordinates to images by selecting a map locations, also in the map panel, where there isn't a close image with data.

I may manually enter data from some other source but you have already identified the four tags in the Default layout as the destination for those. It is unlikely I will do that, but best to know how in any case.