Detect house structures from near-real-time satellite maps/ google maps

Hi all, I'm trying to randomly sample household structures from a satellite map source e.g. google maps. I need to place dots on the image of the roof top and associated each dot with a random IDs. See the attached image; I'd like to put small dots on any structure that looks like a dwelling. Is this possible? I've see a shape detection done for circuler object but never saw one this semi-complex. Please help; thanks :-)