I’m not a fan of Windows 7’s bloat and visual and marketing fluff, but one killer feature that I’ve found genuinely useful in Redmond’s most recent offering is the ability to resize a window to exactly half of the screen by simply dragging it all the way to the left or right of the screen.
As I use an XP development machine at work, I wanted the same functionality on the older generation operating system. Unsusprisingly Microsoft do not provide a way for this feature to be added to XP themselves, but there is a free alternative that does the job; WinSplit-Revolution.
In fact WinSplit-Revolution does more than Windows 7, by allowing you to define a range of sizes for your snap-resized window to take. Whilst this adds a little more complexity to the configuration options, I’ve found it to strike just the right balance between configurable and easy to use, without being a pain to set up. Highly recommended.
I’ve not tried using OpenCV with SL4A myself, but I’d recommend you look into the Python libraries for OpenCV and then use that to do the image processing you’re trying to do – they’ll all work fine in SL4A.
http://opencv.willowgarage.com/documentation/python/