Methods for identifying equipment used in counterfeiting

• US 6,771,796 B2
• Filed: 07/03/2001
• Issued: 08/03/2004
• Est. Priority Date: 10/21/1994
• Status: Expired due to Fees

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Rhoads, Geoffrey B.
• Primary Examiner(s): Johns, Andrew W.
• Application Number:
  US09/898,914
• Publication Number:
  US 20020021825A1
• Time in Patent Office: 1,127 Days
• Field of Search: 382/100, 382/135, 382/232, 713/176, 380/51, 380/54, 380/55, 358/3.28
• US Class Current: 382/100
• CPC Class Codes: B29C 45/1418 the inserts being deformed or preformed, e.g. by the injection pressure
• CPC Class Codes: B42D 25/29 Securities; Bank notes
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 1/005 Robust watermarking, e.g. average attack or collusion attack resistant
• CPC Class Codes: G06T 1/0064 Geometric transfor invariant watermarking, e.g. affine transform invariant
• CPC Class Codes: G06T 1/0071 using multiple or alternating watermarks
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 2201/0065 Extraction of an embedded watermark; Reliable detection
• CPC Class Codes: G06T 7/0002 Inspection of images, e.g. flaw detection
• CPC Class Codes: G07D 7/0034 using watermarks
• CPC Class Codes: G07D 7/004 using digital security elements, e.g. information coded on a magnetic thread or strip
• CPC Class Codes: G10L 19/018 Audio watermarking, i.e. embedding inaudible data in the audio signal
• CPC Class Codes: H04N 1/00002 Diagnosis, testing or measuring; Detecting, analysing or monitoring not otherwise provided for error detection, error correction or monitoring in digital computers or digital computer components G06F11/00
• CPC Class Codes: H04N 1/00005 relating to image data
• CPC Class Codes: H04N 1/00037 Detecting, i.e. determining the occurrence of a predetermined state H04N1/00031 takes precedence
• CPC Class Codes: H04N 1/00092 relating to the original or to the reproducing medium, e.g. imperfections or dirt detecting properties of a sheet H04N1/00681
• CPC Class Codes: H04N 1/00244 with a server, e.g. an internet server fax-servers or the like for store and forward H04N1/324
• CPC Class Codes: H04N 1/00846 based on detection of a dedicated indication, e.g. marks or the like
• CPC Class Codes: H04N 1/00859 Issuing an alarm or the like
• CPC Class Codes: H04N 1/00867 : with additional data, e.g. by adding a warning message details of embedding additional information in an image H04N1/32144
• CPC Class Codes: H04N 1/0087 : with hidden additional data, e.g. data invisible to the human eye
• CPC Class Codes: H04N 1/00875 : Inhibiting reproduction, e.g. by disabling reading or reproduction apparatus
• 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 1/32203 : Spatial or amplitude domain methods H04N1/32309 takes precedence
• 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 1/32219 : involving changing the position of selected pixels, e.g. word shifting, or involving modulating the size of image components, e.g. of characters H04N1/32224 takes precedence
• CPC Class Codes: H04N 1/32261 : in binary data H04N1/32256 takes precedence
• CPC Class Codes: H04N 1/32304 : Embedding different sets of additional information
• CPC Class Codes: H04N 1/32309 : in colour image data
• CPC Class Codes: H04N 2201/3205 : of identification information, e.g. name or ID code H04N2201/3209 takes precedence
• CPC Class Codes: H04N 2201/3207 : of an address
• 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 2201/3233 : of authentication information, e.g. digital signature, watermark
• CPC Class Codes: H04N 2201/3239 : using a plurality of different authentication information
• CPC Class Codes: H04N 2201/3246 : of data relating to permitted access or usage, e.g. level of access or usage parameters for digital rights management [DRM] related to still images
• CPC Class Codes: H04N 2201/3249 : data relating to a linked page or object, e.g. hyperlink
• CPC Class Codes: H04N 2201/327 : which are undetectable to the naked eye, e.g. embedded codes
• CPC Class Codes: H04N 2201/3271 : Printing or stamping
• CPC Class Codes: Y10S 283/901 : Concealed data

Abstract

Line art on a banknote or other security document is slightly changed to effect the encoding of plural-bit digital data (i.e. the banknote is digitally watermarked). When such a banknote is thereafter scanned, the resulting image data can be recognized as corresponding to a banknote by detection of the encoded data. (Alternatively, the image data can be recognized as corresponding to a banknote by machine detection of other forms of watermarking, or by reference to visible structures characteristic of banknotes.) In response to detection of a banknote, the detecting apparatus (e.g., a scanner, photocopier, or printer) can intervene by inserting forensic tracer data (e.g. steganographically encoded binary data) in the image data. The tracer data can memorialize the serial number of the machine that processed the banknote data and/or the date and time such processing occurred. To address privacy concerns, such tracer data is not normally inserted, but is so inserted only when the image data being processed is recognized as corresponding to a banknote. Any printed output from such image data will include the tracer data, permitting identification of equipment used in its reproduction.

Claims

1. A method of image processing, comprising:

providing image data corresponding to an optically scanned document to a processing apparatus; and

digitally watermarking the image data with a machine readable, image-adapted, steganographic digital watermark representing plural bit binary data, said digital watermark serving to mark the image data as having been processed on said apparatus;

wherein said image data thereafter carries said digital watermark embedded therein, permitting the apparatus on which said image data was processed to be identified.

2. The method of claim 1 which includes optically scanning the document to produce said image data.

3. The method of claim 1 in which the digital watermarking makes use of a code signal.

4. The method of claim 1 in which the digital watermarking includes encoding a calibration signal with the plural bit digital data so as to facilitate decoding of the watermark.

5. The method of claim 1 in which the processing apparatus is a scanner.

6. The method of claim 1 in which the processing apparatus is a photocopier.

7. The method of claim 1 in which the processing apparatus is a printer.

8. The method of claim 1 in which the image adaptation of said steganographic digital watermark comprises scaling the digital watermark in accordance with local features of the image data being encoded, so as to minimize visual artifacts.

9. The method of claim 8 in which the watermarking includes summing an image-adapted overlay signal with said image data.

10. A method of image processing, comprising:

providing image data corresponding to an optically scanned document to a processing apparatus; and

digitally watermarking the image data with a machine readable, steganographic digital watermark representing plural bit binary data, said digital watermark serving to mark the image data as having been processed on said apparatus, said watermark not being identifiable from human scrutiny of an image corresponding to said image data;

wherein said image data thereafter carries said digital watermark embedded therein, permitting the apparatus on which said image data was processed to be identified.

11. The method of claim 10 in which the image adaptation of said steganographic digital watermark comprises scaling the digital watermark in accordance with local features of the image data being encoded, so as to minimize visual artifacts.

12. The method of claim 11 in which the watermarking includes summing an image-adapted overlay signal with said image data.

13. A printer, for attachment to a separate computer, the printer including a processor that receives print data from the computer, and translates same into control signals for driving a printing device to produce printed output, characterized in that the processor alters the control signals to introduce a an image adapted steganographic digital watermark into the printed output, wherein said watermark permits the printer to thereafter be identified—

irrespective of the computer with which it is used, and wherein the processor scales the digital watermark in accordance with local features of the print data, so as to minimize visual airfacts.

14. The printer of claim 13 in which the processor sums an image-adapted overlay signal with said control signals.