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 Title: |
US6404899:
Data embedding scheme with error diffusion
[ Derwent Title ]
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| Country: |
US United States of America
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| Inventor: |
Agarwal, Saurabh; New Delhi, India
Aggarwal, Alok; Chappaqua, NY
Bassali, Harpal Singh; New Delhi, India
Chhugani, Jatin; New Delhi, India
Dubey, Pradeep Kumar; New Delhi, India
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| Assignee: |
International Business Machines Corporation, Armonk, NY
other patents from INTERNATIONAL BUSINESS MACHINES CORPORATION (280070) (approx. 44,393)
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| Published / Filed: |
2002-06-11
/ 1999-07-01
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| Application Number: |
US1999000346104
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| IPC Code: |
Advanced:
G06T 1/00;
Core:
more...
IPC-7:
G06K 9/00;
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| ECLA Code: |
G06T1/00W6C; G06T1/00W2;
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| U.S. Class: |
382/100;
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| Field of Search: |
382/100,232,236-248,305,298
380/054,21 D
708/622,402
713/176
712/208,222,226
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| Priority Number: |
| 1999-07-01 |
US1999000346104 |
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| Abstract: |
A method for data embedding in a digital image under the constraint of a pre-specified upper bound value on the amount of change in the value of a property associated with the image. For compression tolerant data hiding in digital images, a property is selected in which the required information can be embedded. The property should be such that the value obtained from the property before and after a lossy compression does not change by a significant amount, and the change should be bounded. The property should be such that a property value as obtained from the image will not vary due to compression, but only due to malicious tampering. The value obtained from the property is stored so that the image can be verified. The complete image is considered in deciding whether to increase or decrease the property value in a particular region. The method also takes into account the fact that blocks having values of 0 or L, corresponding to the minimum and maximum property values, respectively, are incapable of change in a particular region. The method also attempts to vary even the checksum (stored information), in addition to modifying the image so that the net resultant checksum and the modified image coincide with each other.
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| Attorney, Agent or Firm: |
Whitham, Curtis & Christofferson, P.C. ;
Kaufman, Stephen C. ;
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| Primary / Asst. Examiners: |
Patel, Jayanti K.;
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| INPADOC Legal Status: |
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| Parent Case: |
CROSS-REFERENCE TO RELATED APPLICATION
The subject matter of this application is related to the disclosure of patent application Ser. No. 09/273,055 now U.S. Pat. No. 6,246,777 filed Mar. 19, 1999, by Saurabh Agarwal, Alok Agarwal, Harpal Singh Bassali, Jatin Chhugani, and Pradeep Kumar Dubey for "Compression-Tolerant Watermarking Scheme for Image Authentication" and assigned to a common assignee herewith. The disclosure of application Ser. No. 09/273,055 is incorporated herein by reference.
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| Family: |
None
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First Claim:
Show all 10 claims |
Having thus described our invention, what we claim new and desire to secure by Letters Patent is as follows:
1. A computer-implemented method for embedding data in a digital image that is used to authenticate the image, comprising the steps of:
- a) dividing said image into groups of M rectilinear blocks;
- b) calculating a property value of each said block;
- c) defining a mapping function that maps said property value of each said block onto a 0 or a 1 bit;
- d) embedding said 0 or 1 bit associated to each said block in accordance with the following steps, with a variable L=(a1 -b1) when |a1 -b1|<=d, where a1 is a number of microblocks with a first property value equal to a pre-specified lower bound value and having an inherently embedded bit opposite of a bit to be embedded, b1 is a number of microblocks with a second property value equal to a pre-specified upper bound value and having an inherently embedded bit opposite of a bit to be embedded, d is a number of microblocks with a property value between said pre-specified lower bound value and said pre-specified upper bound value and having an inherently embedded bit opposite of a bit to be embedded, I is a macroaverage value, I1 is a quantized macroaverage value, γ is a macroblock property value interval, Δ is an amount by which a change in the microblock property value will not exceed, and D is a set of microblocks with a property value between said pre-specified lower value and said pre-specified upper value and having an inherently embedded bit opposite of a bit to be embedded:
- i) increasing a1 's by Δ;
- ii) decreasing b1 's by Δ;
- iii) increasing a property value associated with each of |L| microblocks of D by Δ when L<0;
- iv) decreasing said property value associated with each of |L| microblocks of D by Δ when L>=0; and
- v) adjusting the remaining D microblocks.
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| Background / Summary: |
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| Drawing Descriptions: |
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| Description: |
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