Timelapse Update
A little while back I blogged about producing a timelapse. That sorted out all of the main issues I had with setting a camera up and leaving it to record a timelapse of a scene.
However I was recently reminded that my daughter had taken a series of daily photos back in in 2010 over an 8 week period whilst a new canteen was built at her school. It was a camera project and something we could use to look back on. All the photos were hand held (and under a range of different times of day and lighting conditions) which created a challenge to producing a timelapse. Most particularly frames were not aligned so I filed the photos under “must do someday”.
Well that day arrived last week!! I realised that the excellent PTGUI which we used on the Studio of Objects project to produce the 360 panoramas has a module that performs image alignment. Now obviously I didn’t want to stitch those photos together (because they would all sit on top of each other!!), but I did want to align them. PTGUI puts the images in to layers and looks for high contrast points between layers to match them. This it did (bar one which I handled manually) and you can then export each layer separately.
Voila a set of aligned images! What this showed was that some of the images were only partially overlapping. Back to the excellent XnView where I specified the crop I wanted and batch processed the images. I now had an aligned timelapse.
I finally did a little bit of experimentation…
1. Colour Toning: I tried “auto-levels” and “auto-contrast” in XnView to try to help colour balance/tone the images. This kinda worked a little bit, but colour toning is complex and doing it across such a diverse range of images very difficult.
2. Overlay: I also wanted to overlay the date and an logo on to the timelapse. XnView has a fabulous overlay facility (”add text”!) which allows you to pull in information from the image itself. The EXIF data in the JPEG had the date and time of exposure, so I changed the font and then added the date to the lower left corner of the frame. After batch processing the images I then realised about 8 images had the wrong date - a friend took photos whilst we were away on holiday and had replaced the batteries in the camera but not reset the date. I thought changing the date in the EXIF header would be easy - but XnView doesn’t do it. That led me to the portable Geosetter which allows you to change a range of image headers including the date. The final step was to add the school logo (”watermark”) and we were done.
Not going to set Hollywood on fire, but satisfying!