feature request: do not overwrite positions of already geotagged photos if time delta is bigger than x

[dieterdreist]

Many mappers nowadays use their smartphones to take photos during a survey. This will in many cases already create geotagged images, but with poor accuracy. An additional GPS track from a dedicated device will usually be able to provide better accuracy, if it was turned on at the specific time of the photo, but accuracy will drop if the GPS recorded its track at a different time.

I propose an additional setting to only overwrite those preexisting geopostions (exif) in the photos where there is an additional gps trackpoint within x seconds (from an external gps). X should be a setting in the dialogue (could default to 30 seconds for overwriting positions and 300-600 for photos without a position).

This way the mappers could keep the smartphone position when there is no related gps track point close to the time the photo was taken and overwrite otherwise the smartphone position with better data from an external device.