US Patent 10198782 Detecting conflicts between multiple different encoded signals within imagery

Various image processing arrangements are detailed for detecting mis-marking of product packaging artwork with two conflicting steganographically-encoded product identifiers. Some embodiments concern detection in a pre-press or test-print quality assurance stage. Others concern detection post-press. All help serve to assure accurate product identification by point of sale scanners. A great number of other features and arrangements are also detailed.