Interpolate GPX points - possible or automatically done?


I am using a GoPro 4 for recording pictures in time lapse mode with a frequency of 0.5s.
For recording the gpx track I am using my smartphone with OsmAnd and a frequency of 1s.
For processing the gps data into the images and uploading to mapillary I am using the mapillary commandline tools.

  1. Not sure if the GoPro in general is able to write subseconds.
    At least I found unprocessed images without them, but processed images with subseconds - so I guess the subseconds are added by mapillary tools?
    Similar to what is mentioned in this thread: What's wrong with my subsecond sequences?

  2. We assume to have pictures with subseconds now. Are the mapillary tools able to interpolate the gpx positions as wells? Since we have two pictures now for each gpx timestamp, both are usually placed on the same location and the second one gets a heading to the north instead of the directions of movement (to the next picture).

Thanks for your support,

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Just some thinking out loud

  • I run the BlackVue mp4>jpg conversion with the tools also at 0.5 seconds
  • After processing, the EXIF (Date and Time Original) does in fact increment by 0.5 seconds
  • As the GPS data is embedded in the mp4 it should all be synced properly
  • Part of the tools process is to export the mp4 GPS data to a GPX file. It has data at 1 second increments and it successfully interpolates to subsecond images.

So to answer Q2, yes the interpolation works. I have no idea re Q1.


Yes, I can confirm that the interpolation is also working with the latest versions of the mapillary tools.
The previous version I used was from around September for uploads by that time.

AT mapillary team: is there something specific about interpolation in your changelog somewhere?

Re: Q1, I am running an old set of Mapillary tools, because I wrote a bash script for it that works for me. It might require a bit more user input than the current iteration, but I like to be able to control for variables/mistakes in data collection.

So I cannot say if the current tools can add subseconds. The old ones that I use do not, so I found a script that someone else wrote (I think mentioned in the thread you linked), and edited for my needs. GoPros do not, as far as I know, write subseconds, even with the latest models. They’re clearly video-first cameras.

I don’t bother with subseconds anymore, though. It’s not worth my time to make sure it works, or storage space for the 50% more photos.