Modulating surface topcoats to embed digital watermarking

Abstract

A gloss value of a clear topcoat (e.g., flood of varnish) on a substrate relative to a bare substrate is an indicator of digital watermark robustness for an encoded signal carried by modulating the clear topcoat. This measurement can be used to predict encoded signal robustness prior to printing. One claim is directed to an image processing method comprising: obtaining a first gloss value corresponding to a layer comprising a matte or gloss topcoat flooded over a substrate; obtaining a second gloss value corresponding to the substrate; and determining a relationship between the first gloss value and the second gloss value to determine digital watermark signal robustness of a sparse mark pattern provided on the substrate with the matte or gloss topcoat. Of course, other claims are combinations are described as well.

Dependencies are inferred from the claim text.