It has been years since I last did this but I remember doing exactly this. It is called exif data. So you would be looking for scripted methods and/or libraries to access this data.

If I had access to the form I would give an example but it is no longer in my archive. Basically I just used stackoverflow examples to get the data I needed.

This only matters if you need to get the location of a picture taken at a different time and uploaded later.

Otherwise you can just use the built in geo coordinate field for capturing the location at time of submission of the form.