The initial task is to process image, hash it, make some heavy image work and store this hash and work results in database, during next request with same image I want to compare the image hashes with hashes I have in database and load database-cached results to reduce amount of heavy work.
So the questions are, what to hash? with what to hash? I see good php implementations of phash but seems to be it is great for similarity check, but we need exact matching. Is phash fine for exact mathing also?
Thank you!