A method is provided for determining whether an object is an authentic object to which an expected encoded image has been applied. The expected encoded image having been constructed by encoding an authentication image using a set of one or more encoding parameters. The method comprises receiving a digital image of at least a portion of the test object including a target area where the expected encoded image would be applied if the test object is an authentic object. The method further comprises determining the one or more encoding parameters and applying a digital decoding algorithm to the captured digital image to establish a decoding result. The decoding result may then be compared to object authentication criteria to establish an authentication result. In particular embodiments of the invention, the actions of receiving, determining, applying and comparing are carried out by an authentication server and the digital image is received from an inspection processor over a network.