When a jpeg already has sufficient geoinformation in its header you can tell exifloc to use it with the --read-gps-tag option. In this case you can omit the --gpx option.
exifloc can only process tracks with date-time information. Older Garmin hand-held receivers store this information in the Active Log but discard it when you save a track.
This program is licensed to you under the GNU General Public License version 3.