The
OpenCV documentation is actually rather good, and I found the
example code to be pretty informative when I was learning OpenCV. I learn best by example, though, so YMMV. If you want a more edited, traditional book, there are a bunch listed
here; you're probably most likely to find the O'Reilly OpenCV book (the first one listed, with the butterfly).
Once you've gone through a few examples, I'd suggest trying to solve one of the past years' challenges (or you can wait until Saturday
). OpenCV is a large enough library that you'll get lost if you try to learn the entire thing without some sort of specific challenge to direct your efforts.
If you have access to the game elements from those years, that would obviously be the best; else I'd suggest looking for pictures on Chief Delphi (ex: Jared from 341 posted some
example camera captures from the 2012 game) or on-robot camera footage off of YouTube (
keepvid.com/). Just try applying some of the filters and see what happens. I'd recommend starting with
smoothing operators,
color-space conversions, and
thresholds. From there, you can move onto
contour analysis and simple shape detection using
Hough transforms.
When it comes to webcams, some are slightly better than others, but in my experience they're all about the same. The real advantage to having another webcam besides the one built into your laptop is that you can easily aim it at things without having to contort yourself and your laptop into weird poses.