So, this time I properly sorted my training data, did some magic on it and tried again.
No, this is not good. The detected text areas are flickering all over the place. It took me a couple of seconds to get this barely decent detection result pop up, and getting this image was about 100% luck, 0% skill. It's not actually detecting text areas, it's still detecting random areas of... something. Anyway, it's mis-trained. Again.
Fortunately I anticipated this, so I'm also running a bunch of other haar training methods in parallel, which should be done tomorrow or so. I still haven't figured out how to properly test the accuracy of my attempts, and because the results have been shit so far I haven't really needed to look into it.
OpenCV/JavaCV notes: I love it. Accessing a webcam in Java in a couple lines of code, and getting better resolution than the Java Media Framework. It's a properly nice library. If only I could get my hands on Intel's Threading Building Blocks, but their site's been down for days. Very annoying.