Printing media and methods employing digital watermarking
First Claim
1. A substrate useful in forming a printed object, characterized in that the substrate has been processed to encode a steganographic digital watermark pattern thereon that does not impair subsequent use of the substrate, yet encodes multi-bit binary data, the presence of said multi-bit binary data not being apparent to a human observer of the printed object, said steganographic pattern being detectable by visible-light scanning of the printed object to yield data from which the multi-bit binary data can be recovered.
6 Assignments
0 Petitions
Accused Products
Abstract
Stationery, or other printable media, is encoded with a digital watermark. The watermark is not conspicuous to a human observer of the media, yet conveys plural bits of auxiliary information when optically scanned and digitally processed. The watermark can be formed by ink-jet printing, or otherwise. The encoded information can be used for various purposes, including authenticating the document as an original, linking to associated on-line resources, and distinguishing seemingly-identical versions of the same document (document serialization).
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Citations
22 Claims
- 1. A substrate useful in forming a printed object, characterized in that the substrate has been processed to encode a steganographic digital watermark pattern thereon that does not impair subsequent use of the substrate, yet encodes multi-bit binary data, the presence of said multi-bit binary data not being apparent to a human observer of the printed object, said steganographic pattern being detectable by visible-light scanning of the printed object to yield data from which the multi-bit binary data can be recovered.
- 17. A method of processing a blank substrate prior to formation of a printed object, the method comprising encoding the substrate with a steganographic digital watermark pattern that does not impair subsequent use of the substrate, yet encodes multi-bit binary data, the presence of said multi-bit binary data not being apparent to a human observer of the printed object, said steganographic pattern being detectable by visible-light scanning of the printed object to yield data from which the multi-bit binary data can be recovered.
- 21. In a method of forming a printable substrate that includes applying plural layers to a film substrate, an improvement comprising tailoring the tone or density of at least one of said layers to form a machine readable indicia encoding plural bits of digital data, the method including mathematically transforming the plural bits of digital data into a two-dimensional array of values, and defining the indicia by reference to the array of values.
Specification