Digital watermarks as a communication channel in documents for controlling document processing devices

• US 20020176116A1
• Filed: 04/11/2002
• Published: 11/28/2002
• Est. Priority Date: 04/12/2001
• Status: Abandoned Application

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Rhoads, Geoffrey B., Patterson, Philip R., Miolla, Ronald S.
• Application Number:
  US10/121,434
• Publication Number:
  US 20020176116A1
• Time in Patent Office: Days
• US Class Current: 358/405
• CPC Class Codes: G06F 21/608 Secure printing
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: H04N 1/00968 by scanning marks on a sheet mark-sheet input means H04N1/00355; sensing record carriers G06K7/00
• CPC Class Codes: H04N 1/32144 embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
• CPC Class Codes: H04N 1/32208 involving changing the magnitude of selected pixels, e.g. overlay of information or super-imposition H04N1/32219, H04N1/32224 take precedence
• CPC Class Codes: H04N 1/32293 Repeating the additional information in a regular pattern
• CPC Class Codes: H04N 2201/3212 of data relating to a job, e.g. communication, capture or filing of an image
• CPC Class Codes: H04N 2201/3222 of processing required or performed, e.g. forwarding, urgent or confidential handling
• CPC Class Codes: H04N 2201/3226 of identification information or the like, e.g. ID code, index, title, part of an image, reduced-size image
• CPC Class Codes: H04N 2201/3242 of processing required or performed, e.g. for reproduction or before recording H04N2201/3256 and subgroups take precedence
• CPC Class Codes: H04N 2201/3247 Data linking a set of images to one another, e.g. sequence, burst or continuous capture mode
• CPC Class Codes: H04N 2201/327 which are undetectable to the naked eye, e.g. embedded codes

Abstract

Digital watermarks are embedded in documents to create a communication channel between document handling devices such as copiers, printers, scanners and fax machines. The digital watermarks are used to control document reproduction and transmission operations. The digital watermarks are also used to embed transaction information in documents, to link the document to an original, electronic version stored on a network, to trace the document handling history of a document, etc.

Claims

1. A document carrying a document control instruction in a digital watermark signal embedded on the document, the document control instruction including an instruction for controlling fax transmission or reproduction of the document.

2. The document of claim 1 wherein the digital watermark comprises a spread spectrum modulated image signal embedded in a document image on one or more pages of the document.

3. The document of claim 2 wherein the spread spectrum modulated signal is a background tint over which information content of the document is superimposed.

4. The document of claim 3 wherein the information content includes text characters that are superimposed over the background tint.

5. The document of claim 3 wherein the spread spectrum modulated signal is embedded in the document by modulating line widths in a rasterized version of text content of the document.

6. The document of claim 3 wherein the spread spectrum modulated signal is embedded in the document by modulating half tone dots to create variations in luminosity of the document in accordance with the spread spectrum modulated signal.

7. The document of claim 1 wherein the instruction includes a fax control instruction to instruct a fax machine to send the document to a particular destination.

8. The document of claim 1 wherein the instruction includes a reproduction control instruction that controls re-production of a designated portion of the document.

9. The document of claim 1 wherein the instruction specifies a group of users or devices that are allowed to reproduce the document.

10. The document of claim 1 wherein the instruction specifies a group of users or devices that are allowed to receive a fax transmission of the document.

11. The document of claim 1 wherein the instruction includes an index to a memory location where an original, electronic version of the document is stored.

13. The fax machine of claim 12 wherein the transaction information includes a time stamp of the fax transmission.

14. The fax machine of claim 12 wherein the transaction information includes information about an origination address or destination address of the fax transmission.

16. The document reproduction device of claim 15 wherein the instruction includes an index to a database that lists devices or users that are authorized to reproduce the document.

18. The document of claim 1 wherein the instruction is operable to instruct a fax machine receiving the document to acknowledge receipt of the document to a sending fax machine.

19. The document of claim 1 wherein the digital watermark is operable to indicate whether the document has been altered by measuring strength of the watermark signal.

20. The document of claim 19 wherein the strength of the watermark signal is measured by measuring bit errors of an error correction encoded message embedded in the watermark.

21. The document of claim 19 wherein the watermark is replicated in tiles spread over the document, and detection of the watermark tiles enables location of one or more altered parts of the document to be identified.

22. The document of claim 19 wherein the digital watermark includes a fragile component that degrades in response to alteration of the document and a robust component embedded more robustly than the fragile component for carrying the document control instruction.

12. A fax machine including a digital watermark embedder for combining a rasterized version of a document with a digital watermark signal, the digital watermark recording transaction information about a fax transmission of the document.

15. A document reproduction device including a digital watermark embedder for combining a rasterized version of a document with a digital watermark signal, the digital watermark including an instruction that limits reproduction of some or all of the document to a predetermined group of devices or users.

17. A document processing device including a digital watermark reader for extracting a message payload embedded in a document and accessing a database entry to record a transaction event to track reproduction or faxing of the document.