Declarationproperty EXIF_GPSAltitudeRef: AnsiString;
Returns the altitude used as a reference:
- If the reference is sea level and the altitude is above sea level, "0" is returned.
- If the altitude is below sea level, a value of "1" is returned and the altitude is indicated as an absolute value in the EXIF_GPSAltitude
The reference unit is meters.
Default value is empty string, which means "unknown". An unknown value is not written when saving EXIF values.
Note: To save GPS data, you must set EXIF_GPSVersionID
to '188.8.131.52' (or use the const, GPS_Version_ID