Data embedding

• US 5,659,726 A
• Filed: 02/23/1995
• Issued: 08/19/1997
• Est. Priority Date: 02/23/1995
• Status: Expired due to Fees

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Handel, Theodore G., Sandford, Maxwell T. II
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): Lintz, Paul R.
• Application Number:
  US08/392,642
• Time in Patent Office: 908 Days
• Field of Search: 395/600, 380/54, 380/49, 380/4
• US Class Current: 1/1
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 2201/0083 whereby only watermarked image required at decoder, e.g. source-based, blind, oblivious
• CPC Class Codes: H04N 1/32149 Methods relating to embedding, encoding, decoding, detection or retrieval operations
• CPC Class Codes: H04N 1/32251 in multilevel data, e.g. greyscale or continuous tone data
• CPC Class Codes: H04N 1/32309 in colour image data
• CPC Class Codes: H04N 2201/3233 of authentication information, e.g. digital signature, watermark
• CPC Class Codes: H04N 2201/327 which are undetectable to the naked eye, e.g. embedded codes
• CPC Class Codes: H04N 2201/3274 Storage or retrieval of prestored additional information
• CPC Class Codes: H04N 7/08 Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band , e.g. by time division H04N7/007 takes precedence

Abstract

A method of embedding auxiliary information into a set of host data, such as a photograph, television signal, facsimile transmission, or identification card. All such host data contain intrinsic noise, allowing pixels in the host data which are nearly identical and which have values differing by less than the noise value to be manipulated and replaced with auxiliary data. As the embedding method does not change the elemental values of the host data, the auxiliary data do not noticeably affect the appearance or interpretation of the host data. By a substantially reverse process, the embedded auxiliary data can be retrieved easily by an authorized user.

Claims

1. A method of embedding auxiliary data into host data comprising the steps of:

creating a digital representation of said host data in the form of elements having numerical values and containing a noise component;

creating a digital representation of said auxiliary data in the form of a sequence of INDIVIDUAL bit VALUES;

evaluating said noise component of said digital representation of said host data;

comparing pairs of said elements with said noise component to determine pairs of said elements having numerical values which differ by less than said value of said noise component;

replacing individual values of said elements with substantially equivalent values from said pairs of elements in order to embed individual bit values of said auxiliary data corresponding to said sequence of bit values of said auxiliary data; and

outputting said host data with said auxiliary data embedded into said host data as a file.

2. The method as described in claim 1 further comprising the step of combining said auxiliary data with predetermined information indicative of said auxiliary data, its file name, and file size, said step to be performed after the step of digitizing said auxiliary data.

3. The method as described in claim 1 further comprising the step of determining a protocol for embedding said auxiliary data into said host data which allows for verification of said auxiliary data upon extraction from said host data.

4. The method as described in claim 1, wherein said host data comprises a color photograph.

5. The method as described in claim 1, wherein said host data comprises a black and white photograph.

6. The method as described in claim 1, wherein said host data comprises a television signal.

7. The method as described in claim 1, wherein said host data comprises a painting.

8. The method as described in claim 1, wherein said host data comprises a facsimile transmission.

9. The method as described in claim 1, wherein said host data comprises an identification card.

10. The method as described in claim 1, wherein said host data comprises digital audio information.