I like this idea, but I'd probably opt for reading the stats out of memory instead of OCRing them. You'd get more data (since you don't need to have only one specific tab open), it'd be more accurate, and it might even be easier.

If anyone is unfamiliar with reading process memory in Windows and wants to do this, I have a fairly simple example reading from SC2 at https://github.com/gibybo/S2GS-Extractor