1. Frank Becker
  2. gps2exif



gps2exif - GPS-tagging of JPEG files

gps2exif reads .gpx files and tags JPEG images according to the time they have been taken. It allows to fix image date/time and interpolates between GPS points.

General syntax

gps2exif [-h] [-n] [-v] [--gpx GPX] [--ref-img REF_IMAGE] [--ref-time REF_TIME] [--shift-time SHIFT_TIME] [--max-dist MTRS] [--max-span SECS] [--ok-dist MTRS] [--ok-span SECS] IMAGE [IMAGE ...]

You can give multiple .gpx files using the '--gpx FILE' switch multiple times. Give the names of the image files to be processed at the end of the command line. The switch '-n' will make a dry-run and not change any file. The '-v' switch increases verbosity.

Fixing image date/time

A precise date/time stored in the image's EXIF data is crucial for associating the GPS track with the image. gps2exif offers two ways to fix the date/time stored in the JPEG files before looking up the GPS coorinates:

  • You can either give the name of a file and the correct date/time of the file. gps2exif will calculate the time offset and apply it to all given images. This is ideal if you took a photo of your GPS device showing GPS time.

    The syntax is '--ref-img REF_IMAGE --ref-time REF_TIME'. REF_TIME should be formatted like '2011-10-22 14:42:07'.

  • If you know the time offset, you can give it via '--shift-time SHIFT_TIME'. For example, use '--shift-time=+1:09' to add 1 minute, 9 seconds to the time of each image.

Setting thresholds

Under some circumstances GPS devices do not store enough points to make a precise-enough guess about the location a photo was taken at. You can set the thresholds that control whether the GPS data is deemed good enough or not.

The thresholds are checked on the two GPS points around the time your photo was taken: the last GPS point before and the first GPS point after the time of your photo. You can set thresholds on the time span and the distance between these two GPS points.

With '--max-dist MTRS' and '--max-span SECS' you set hard thresholds. A photo will not be GPS-tagged if the two enclosing GPS points are more than MTRS meters or more than SECS seconds apart.

With '--ok-dist MTRS' and '--ok-span SECS' you set the okay criteria. A photo will not be GPS-tagged if the two GPS enclosing points are neither closer than MTRS meter nor closer than SECS seconds.

To GPS-tag a photo always both max criteria and at least one ok criterion must be met.