1. A method, comprising: configuring at least two conjugate halftone screens having respective halftone signal levels thereof to provide a basic information carrier for embedding a digital watermark into a document; automatically generating from said at least two conjugate halftone screens for each respective halftone signal level at least two clusters of varying shape due to differences among said at least two conjugate halftone screens, such that thereafter at each of all halftone signal levels thereof, said at least two clusters, due to varying conjugate screens among said at least two conjugate screens, comprise a same cluster size and a same centroid position relative to a grid defined by fundamental halftone frequencies; and arbitrarily blending two halftone patterns from said at least two-conjugate halftone screens in a cluster-to-cluster basis so that virtually no loss of image quality occurs in comparison with an output of either one of said at least two-conjugate halftone screens, thereby permitting said digital watermark to be embedded into said document utilizing said at least two-conjugate halftone screens.