Timelapse: Creating an Inset Map

Friday, 18 December, 2015

Last month I blogged about an update to my workflow for creating a timelapse and particularly adding overlays (both graphics and text from EXIF data) and solving problems with dates being out-of-sync by timeshifting them.

Well that flurry of activity made me think about the data I collected for my Durness-to_Dover bike ride. For that I used a GoPro attached to the front of my bike and took a photo every 30s along the entire ~800 mile route. I turned those in to straight timelapse videos and thought nothing more of it until recently. In tandem with the photography my biking partner had a cycle satnav with our route planned on it that also kept a tracklog of the route we actually took. What struck me was that the GPS tracklog would have had the correct times stored in it and that I now knew how to timeshift the images. A further look at ExifTool showed that it could not only write coordinates in to the EXIF headers of the photos, but also read the tracklogs straight out of the GPS, find the nearest points based upon time and interpolate between them to give a very good estimate of actual position.

Critically then I was now able to use the tracklog to timesync the photos and geocorrect them. What I thought would could now do was:

1. Time Overlay: insert the time of the photo, having that increment through the video
2. Inset Map: create an inset map with a point showing the position of the photo. This would then animate over the video, moving as day progressed.

Over the next few posts I’ll outline how I built this up (with a little help!), but below is the end product, so you can see what the final result was!