Does Picasa store photo geotagging in IPTC tags or in its DB?

Question

I've recently done a small test of Picasa, and was very impressed by its geographic presentation (the Google maps integration is way nicer than what I previously used - Microsoft Expression Media). So, as a follow-up, I tried to geo-tag a photo in Picasa, and was disapointed to see that the file was not updated in OS. So.

Does Picasa really store geotagging in photo files ?

Or does it save this information in its non-standard, vendor-lockin DB ? And if so, is there a way to transfer this locked information into IPTC tags ?

Answer 1

After @exinocactus answer, I took the time to perform a test.

So I took a photo having no Lat/Long information, and displayed it in Picasa. It showed without the little red marker. I then added the geotag, and the red marker showed up. A latter verification in Windows Explorer ensured me that, indeed, Lat/Long were correctly stored in IPTC tags.

So, the answer is definitely YES : Picasa stores Lat/long in IPTC tags.

Next step is obviously : how to be DRY with photos locations ? That's to say how to reverse geocode the lat/long fields into existing addresses ?

Answer 2

I made some tests also, when a photo contains geo Tags, they are initially used by picasa. If you change the location in picasa (shift the loc-tag) than it is only changed in the .picasa.ini file, and it overrides the photo tags.

I set a tag with geosetter in a raw photo file. Started picasa - it got the file, showed the right location. Then I changed the location in picasa, stopped picasa. I changed the photo tag outside by geosetter, started picasa, waited until it updated the photo.

But picasa does not show the new geosetter location, it shows its old changed location. I looked in the .picasa.ini and there is the changed location from picasa, while the raw file holds the other changed location from geosetter.

Answer 3

Picasa implements non-destructive photo editing and stores information about file corrections in the sidecar files in the same directory (at least it used to do so until recently). That's where the coordintates should be initially saved as well.

Only when you export photo form the program, the modifications including adding the geotag get applied to the newly created files.