Posts tagged with “as3” and “multitouch”
Detecting blobs at the speed of light
While working on my eye tracking experiment I got to the point where I needed to execute a blob detection algorithm to determine relative positioning of the eyes. I found some really good blob detection algorithms but I didn't have enough time to try implementing them. Andrei R. Thomaz had ported an existing Processing library (based on subdivision), but it turned out to be too slow/complicated to fit for my needs.
Few days ago while looking for something else, I've found this genius object detection technique by japanese guy Kynd (developed from the original code by Kampei Baba). I decided to try it out for detecting blobs.
UPDATE: This blob detection method has also been discovered by Quasimondo and was shown (!) at Flash on the Beach 2007. It hasn't enough spread as Mario hadn't released the source.
You can test the result below, try it yourself. First, click the Flash area to activate, then click anywhere to add more blobs. You can also press space to toggle debug mode on/off.
I was totally amazed how fast (and exact) it performs! Believe or not but the main blob detection routine has only a few lines of code.
How does it work then?
It's really very simple – the secret lays in utilising the native floodFill Flash Player method in conjunction with getColorBoundsRect.
Here's how (after the jump).