For example, you see a small part of a curtain picture, but from this small part you are able to recognize that this is a "curtain".
Or if your sight is hazy, and you can recognize an object because of its general outline.
My thoughts were on "make out", "discern", or "differentiate". But the last 2 sound more like "recognize from a group of similar looking objects".
So, what's the best word for above case?