Very good. Yes, standard practice is to "shrink" the images by hashing. Thus you obtain another token for your image, in fact a non-fungible token for your image, because the hash was a cryptographic one. This means that the hash is irreversible, ownership of the images hash-token is the same thing as just ownership of the image. There is no change in scarcity at this stage.

I think we may have found a critical point of confusion here, in speaking of hashing. When I (or the smart contract) hashes an image, we are scrambling the image with an asymmetric hashing. It's not a simple checksum, is what I mean. So hashing the image can only be done with the owners public key, and the resulting hash is hers to unlock— she needs no external oracle, she has her private key.

Are we still in agreement?