Motion Detection for Video Files

April 11, 2011 6:09 PM

Is there a program or set of tools, preferably free / open source, that can take a video file as input, analyze the video, and output the parts of the video which contain motion above some threshold? The output could either be a video file or a series of still images.
posted by Juffo-Wup to Computers & Internet (7 answers total)

Best answer: Motion is pretty much exactly what you're looking for.
posted by kdar at 6:13 PM on April 11, 2011

Matlab also has a set of libraries/toolbox that do this is you are looking to do more analysis which would be easier in that type of environment
posted by trialex at 6:31 PM on April 11, 2011

Roborealm is an interesting Windows program that lets you do things like this with live video feeds such as from a web camera or a video file. Try the trial, and get the hang of things by using a web camera.
posted by JesseBikman at 6:34 PM on April 11, 2011

Response by poster: Motion looks ideal, except that I need to do the motion detection on pre-recorded video files as opposed to live camera streams. In looking through the Motion docs, I didn't see any option for using a video file as a source, but I will read in more detail tomorrow. I will also take a look at Roborealm, although something that can run on *NIX would be ideal. Thanks for all the ideas so far!
posted by Juffo-Wup at 9:08 PM on April 11, 2011

ImageJ is neat, it also has plugins.

Might do what you want with some input, found some hits below.

Hit1
Hit2
Hit3
Hit4
posted by gallagho at 2:03 AM on April 12, 2011

OpenCV (CV stands for Computer Vision):
http://en.wikipedia.org/wiki/OpenCV
http://opencv.willowgarage.com/documentation/cpp/imgproc_motion_analysis_and_object_tracking.html

You may be able to use simple frame subtraction:
http://www.youtube.com/watch?v=KREoXEy9ojY

O'reilly's book, chapter 9, is a good place to start (code downloadable also):
http://oreilly.com/catalog/9780596516130

might search on "video summarization" and "video skimming"
posted by at at 5:20 AM on April 12, 2011

Response by poster: I'd still like an easy way to process pre-recorded files, but using Motion with a live stream has solved the immediate problem. Thanks, everyone!
posted by Juffo-Wup at 9:46 AM on April 13, 2011