SUMMARY I have pictures with invalid GPS data. Digikam displays them as located at Equator. The GPS are invalid because all fields are 0 (except the date). ExifTool says: GPS Altitude : 0 m Above Sea Level GPS Latitude : 0 deg 0' 0.00" N GPS Longitude : 0 deg 0' 0.00" E GPS Position : 0 deg 0' 0.00" N, 0 deg 0' 0.00" E OBSERVED RESULT Digikam displays them at Equator (as though lat=0, long=0), but clearly this is wrong (values of lat, long, at altitute are exactly 0) EXPECTED RESULT Digikam should consider that there is no valid GPS data ADDITIONAL INFO 1) See example of such picture: https://nicofo.tuxfamily.org/tmp/Example_with_Lat=Lon=Alt=0.jpg 2) Note: I don't know if this can be related to https://bugs.kde.org/show_bug.cgi?id=326406#c26
Some camera provides indications about the quality of signal (as DLSR), other no (as cellulars). For example: * From my Iphone 15 pro: >>> Global Positioning System <<< GPS Altitude : 165.4 m GPS Altitude Reference : Above sea level GPS Date Stamp : 2025:10:26 GPS Destination Bearing : 105.403 GPS Destination Bearing Reference : Magnetic direction GPS Horizontal positioning error : 6.47503 GPS Image Direction : 105.403 deg GPS Image Direction Reference : Magnetic direction GPS Latitude : 43 deg 38' 52.18" GPS Latitude Reference : North GPS Longitude : 3 deg 20' 26.30" GPS Longitude Reference : East GPS Speed : 0.66727 GPS Speed Reference : km/h GPS Time Stamp : 12:13:33 * From my Sony A77 i can see more details : >>> Global Positioning System <<< GPS Altitude : 156.6 m GPS Altitude Reference : Above sea level GPS Data Degree of Precision : 1.4247 GPS Date Stamp : 2015:07:23 GPS Differential : Without correction GPS Latitude : 43 deg 39' 7.64" GPS Latitude Reference : North GPS Longitude : 3 deg 21' 49.53" GPS Longitude Reference : East GPS Map Datum : WGS-84 GPS Measure Mode : 3-dimensional measurement GPS Speed : 0.292 GPS Speed Reference : km/h GPS Status : Measurement in progress GPS Time Stamp : 11:57:17 GPS Track : 60.53 deg GPS Track Ref : True direction GPS Version ID : 2.3.0.0 So the limited information about the GPS quality of signal cannot be used everywhere to judge if the Geolocation are valid or not. Gilles Caulier
Just because the latitude, longitude, and altitude are 0 doesn't invalidate the coordinates. While it's unlikely the image was taken at exactly that location, it's possible. We also have a valid GPS date and time stamp. The metadata contains no other information, such as the number of satellites, that could be used to verify the coordinates' accuracy. For me, this is not a bug in digiKam, but rather a bug in the camera/smartphone; it should not make a GPS entry in the metadata if no coordinates are available. Maik
(In reply to Maik Qualmann from comment #2) > Just because the latitude, longitude, and altitude are 0 doesn't invalidate > the coordinates. While it's unlikely the image was taken at exactly that > location, it's possible. We also have a valid GPS date and time stamp. The > metadata contains no other information, such as the number of satellites, > that could be used to verify the coordinates' accuracy. > > For me, this is not a bug in digiKam, but rather a bug in the > camera/smartphone; it should not make a GPS entry in the metadata if no > coordinates are available. > > Maik I expected that answer, and I understand it - indeed I have not found exif field in my picture that would allow us to invalidate the GPS data. The (0,0) coordinates is valid even if totally unlikely. This is even called the "Null Island" (https://en.wikipedia.org/wiki/Null_Island), known because a lot of software associate the GPS location of invalid pictures there. This shows that a lot of camera/smartphone use these coordinates when they don't have a valid GPS information. Because 99.9999...% of pictures with (0,0) have invalid data, I would consider (0,0) as invalid. What do you think ?
Okay, you've convinced me ((:-)) Maik