An automated method of producing an encoded image for use in
authenticating a printed version of a digital document is presented. The
method comprises establishing at least one digitized authentication
image, receiving at least one user-supplied encoding parameter, and
determining at least one non-user-supplied encoding parameter. The method
further comprises establishing a first encoding parameter set including
the at least one user-supplied encoding parameter and the at least one
non-user-supplied encoding parameter. The first encoding parameter set is
usable to encode one or more of the at least one digitized authentication
image. The method also comprises encoding one or more of the at least one
digitized authentication image using the first encoding parameter set to
produce a final encoded image.