Yes, it is ok to ask and answer your own question, but one must show a bit of restraint as well. To clarify, new users on other busier sites often try to ask and answer what they think is an interesting tidbit or a solution to their localized, under-described, problem, in the spirit of that blogpost. However, I think that such self-answers will have lasting value only if the underlying issue is well explained and the answer thorough. Self-answers to a hard problem (even if partial) can also help others who are late to the party to know where you're at and give them a spring board to tackle your problem, so to aid that, it needs to be adequate.
In this specific case, I agree that the particular user has been asking several questions in the same vein (sorry, couldn't resist :P) and a canonical question & answer will help. If I may suggest a direction for your endeavor, I would recommend not focusing on their particular image and problem, but instead on the concepts and theory (and maybe some code, if you're interested) that is necessary to solve their problem — that's what this site is for. That would definitely be a useful resource and we can also close all future identical questions as a duplicate of yours.