What is the simplest way to check if two images are the same?

Question

I'm not talking titles / name, I mean pixel analyzation or perhaps bitmapping... perhaps an OCR?

I need to reduce the server usage by not using duplicate media so if a person is trying to upload a photo that is already on the server uploaded by someone else, that photo will not be uploaded.

Answer 1

I do not know about the what technology you are using.

But, I believe you may use md5 check for that. MD5 check are a good way to solve file comparison and it has for a lot of technologies.