System and method for lossless data hiding using the integer wavelet transform

• US 20060120558A1
• Filed: 10/17/2005
• Published: 06/08/2006
• Est. Priority Date: 10/20/2004
• Status: Abandoned Application

• Current Assignee: New Jersey Institute of Technology
• Original Assignee: New Jersey Institute of Technology
• Inventors: Shi, Yun-Qing, Xuan, Guorong
• Application Number:
  US11/252,155
• Publication Number:
  US 20060120558A1
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 2201/0052 Embedding of the watermark in the frequency domain
• CPC Class Codes: G06T 2201/0083 whereby only watermarked image required at decoder, e.g. source-based, blind, oblivious
• CPC Class Codes: G06T 2201/0203 whereby the image with embedded watermark is reverted to the original condition before embedding, e.g. lossless, distortion-free or invertible watermarking
• CPC Class Codes: H04N 1/3217 using wavelet transforms
• CPC Class Codes: H04N 1/32187 with selective or adaptive application of the additional information, e.g. in selected frequency coefficients
• CPC Class Codes: H04N 1/32192 according to calculated or estimated visibility of the additional information in the 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 2201/327 which are undetectable to the naked eye, e.g. embedded codes

Abstract

A system and method are disclosed which may include subjecting an original, pixel domain image to an Integer Wavelet Transform (IWT) to obtain a first matrix of IWT coefficients; multiplying selected ones of the IWT coefficients by two; and embedding a data bit in a LSB (Least Significant Bit) position of each selected coefficient, thereby providing a marked image.

Claims

1. A method, comprising:

subjecting an original, pixel domain image to an Integer Wavelet Transform (IWT) to obtain a first matrix of IWT coefficients;

multiplying selected ones of said IWT coefficients by two; and

embedding a data bit in a LSB (Least Significant Bit) position of each said selected coefficient, thereby providing a marked image.

2. The method of claim 1 wherein said selected IWT coefficients are selected from at least one frequency sub-band of said matrix of IWT coefficients.

3. The method of claim 2 wherein said at least one frequency sub-band comprises at least one frequency sub-band selected from the group consisting of:

an HL sub-band, an LH sub-band, and an HH sub-band.

4. The method of claim 1 further comprising:

narrowing a histogram of said original image prior to said multiplying.

5. The method of claim 4 further comprising:

recording said narrowing of said histogram with histogram modification data; and

embedding said histogram modification data in said image.

6. The method of claim 1 further comprising:

applying a compression function to said first matrix of IWT coefficients to provide a second matrix of compressed IWT coefficients.

7. The method of claim 6 wherein said compression function is a piecewise linear function, and wherein the method further comprises:

quantizing said piecewise linear function to provide;

a) a first segment of said quantized piecewise linear function having a one-to-one mapping between a first group of said IWT coefficients within said first matrix and a first group of said compressed IWT coefficients within said second matrix; and

b) a second segment of said quantized piecewise linear function having a many-to-one mapping between a second group of said IWT coefficients within said first matrix and a second group of said IWT coefficients within said second matrix.

8. The method of claim 7 further comprising:

generating compression recording data enabling reversing said many-to-one mapping in said second segment of said quantized piecewise linear function; and

storing said compression recording data in said IWT coefficients of said second matrix.

9. The method of claim 7 wherein said one-to-one mapping in said first segment of said quantized piecewise linear function is implemented employing the function F(x)=x.

10. The method of claim 1 wherein said multiplying step comprises:

multiplying by two only those IWT coefficients that have absolute values less than a threshold value (T).

11. The method of claim 10 further comprising:

selecting a value of T by a human operator.

12. The method of claim 10 further comprising:

selecting a value of T employing a software program running on a computer.

13. The method of claim 10 further comprising:

adding T to IWT coefficients having values greater than or equal to T.

14. The method of claim 10 further comprising:

subtracting the value (T−

1) from IWT coefficients having values less than or equal to −

T.

15. An apparatus including a processor operating under the instructions of a software program, the software program causing the apparatus to perform actions, comprising:

subjecting an original, pixel domain image to an Integer Wavelet Transform (IWT) to obtain a matrix of IWT coefficients;

multiplying selected ones of said IWT coefficients by two; and

embedding a data bit in a LSB (Least Significant Bit) position of each said selected coefficient, thereby providing a marked image.

16. A storage medium containing a software program operable to cause an apparatus including a processor under the instructions of the software program to perform actions, comprising:

subjecting an original, pixel domain image to an Integer Wavelet Transform (IWT) to obtain a matrix of IWT coefficients;

multiplying selected ones of said IWT coefficients by two; and

embedding a data bit in a LSB (Least Significant Bit) position of each said selected coefficient, thereby providing a marked image.

17. A method, comprising:

subjecting a marked pixel domain image to an Integer Wavelet Transform (IWT) to obtain a first matrix of IWT coefficients;

identifying coefficients in said matrix that contain embedded payload data; and

extracting data bits from LSB positions of said identified coefficients.

18. The method of claim 17 further comprising:

dividing said identified coefficients by two to restore a value of said coefficients in existence prior to an introduction therein of said embedded payload data.

19. The method of claim 17 further comprising:

extracting histogram modification data from said first matrix of wavelet coefficients, said histogram modification data describing a modification of a histogram of an original version of said marked pixel domain image.

20. The method of claim 19 further comprising:

subjecting said matrix of IWT coefficients to an inverse integer wavelet transform to obtain an unmarked pixel domain image; and

modifying a histogram of said unmarked pixel-domain image using said histogram modification data to provide said original pixel-domain image.

21. The method of claim 17 further comprising:

applying an expansion function to said IWT coefficients of said first matrix to provide expanded IWT coefficients in a second matrix of IWT coefficients.

22. The method of claim 21 wherein said expansion function is a quantized piecewise linear function comprising:

a first segment of said quantized piecewise linear function having a one-to-one mapping between a first group of said IWT coefficients of said first matrix and a first group of said expanded IWT coefficients of said second matrix; and

a second segment of said quantized piecewise linear function having a one-to-many mapping between a second group of said IWT coefficients of said first matrix and a second group of said IWT coefficients of said second matrix.

23. The method of claim 22 further comprising:

extracting compression recording data from said IWT coefficients of said first matrix; and

using said extracted compression recording data to conduct said one-to-many mapping of said second segment of said quantized piecewise linear function.

24. The method of claim 17 further comprising:

subtracting a threshold value (T) from IWT coefficients having values greater than or equal to 2T.

25. The method of claim 17 further comprising:

adding the value (T−

1) to IWT coefficients having values less than or equal to 2T−

1.

26. An apparatus including a processor operating under the instructions of a software program, the software program causing the apparatus to perform actions, comprising:

subjecting a marked pixel domain image to an Integer Wavelet Transform (IWT) to obtain a matrix of wavelet coefficients;

identifying coefficients in said matrix that contain embedded payload data; and

extracting data bits from LSB positions of said identified coefficients.

27. A storage medium containing a software program operable to cause an apparatus including a processor under the instructions of the software program to perform actions, comprising:

subjecting a marked pixel domain image to an Integer Wavelet Transform (IWT) to obtain a matrix of wavelet coefficients;

identifying coefficients in said matrix that contain embedded payload data; and

extracting data bits from LSB positions of said identified coefficients.

28. A method, comprising:

subjecting an original, pixel domain image to an Integer Wavelet Transform (IWT) to obtain a matrix of IWT coefficients located within a plurality of frequency sub-bands;

selecting at least one of said sub-bands;

embedding a payload data bit only in coefficients within said selected at least one sub-band whose absolute values are less than a threshold (T).

29. The method of claim 28 wherein said embedding step comprises:

multiplying by two said coefficients having absolute values less than T; and

placing said payload data bits in respective LSB (least significant bit) positions of said multiplied coefficients.

30. The method of claim 28 wherein said selecting comprises:

selecting said at least one sub-band from the group consisting of;

an HL sub-band, an LH sub-band, and an HH sub-band.

31. An apparatus including a processor operating under the instructions of a software program, the software program causing the apparatus to perform actions, comprising:

subjecting an original, pixel domain image to an Integer Wavelet Transform (IWT) to obtain a matrix of IWT coefficients located within a plurality of frequency sub-bands;

selecting at least one of said sub-bands;

embedding a payload data bit only in coefficients within said selected at least one sub-band whose absolute values are less than a threshold (T).

32. A storage medium containing a software program operable to cause an apparatus including a processor under the instructions of the software program to perform actions, comprising:

subjecting an original, pixel domain image to an Integer Wavelet Transform (IWT) to obtain a matrix of IWT coefficients located within a plurality of frequency sub-bands;

selecting at least one of said sub-bands;

embedding a payload data bit only in coefficients within said selected at least one sub-band whose absolute values are less than a threshold (T).