Image processing apparatus and method, computer program, and computer-readable storage medium

• US 20040001609A1
• Filed: 06/23/2003
• Published: 01/01/2004
• Est. Priority Date: 06/28/2002
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Murakami, Tomochika
• Granted Patent: US 7,269,272 B2
• 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 1/0092 Payload characteristic determination in a watermarking scheme, e.g. number of bits to be embedded
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 2201/0061 Embedding of the watermark in each block of the image, e.g. segmented watermarking
• 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

Abstract

This invention can multiplex noise in multilevel image data to reversibly embed visible additional information with a noise-multiplexed distribution while maintaining the atmosphere of the multilevel image data subjected to embedding. For this purpose, when noise is multiplexed on multilevel image data to embed visible additional information with a noise-multiplexed distribution, information representing whether or not to multiplex noise for each pixel is input as the additional information. Whether a pixel of interest in the multilevel image data is located at a position where noise is to be multiplexed is determined on the basis of the additional information (S106). When the pixel of interest is determined to be located at the position where noise is to be multiplexed, a bit region where noise is to be multiplexed in the pixel of interest is specified on the basis of data in a region near the pixel of interest (S110). Bit information is reversibly changed in the specified bit region of the pixel of interest (S112, S114).

Claims

1. An image processing apparatus which multiplexes noise on multilevel image data to embed visible additional information with a noise-multiplexed distribution, comprising:

input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel;

determination means for determining on the basis of the additional information whether a pixel of interest in the multilevel image data is located at a position where noise is to be multiplexed;

specifying means for, when said determination means determines that the pixel of interest is located at the position where noise is to be multiplexed, specifying a bit region where noise is to be multiplexed on the basis of data of a neighboring region near the pixel of interest; and

change means for reversibly changing bit information for the bit region of the pixel of interest specified by said specifying means.

2. The apparatus according to claim 1, further comprising means for setting information on an intensity for multiplexing noise, and

said specifying means specifies the bit region where noise is to be multiplexed on the basis of the set information on the intensity and data of the neighboring region.

3. An image processing apparatus which removes visible additional information from multilevel image data in which noise is reversibly embedded to multiplex the visible additional information, comprising:

input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel;

determination means for determining on the basis of the additional information whether a pixel of interest in the multilevel image data is located at a position where noise is multiplexed;

specifying means for, when said determination means determines that the pixel of interest is located at the position where noise is multiplexed, specifying a bit region where noise is multiplexed on the basis of data of a neighboring region having undergone removal processing near the pixel of interest; and

reconstruction means for performing conversion inverse to noise multiplexing to reconstruct a state of the bit region of the pixel of interest specified by said specifying means into a state before multiplexing.

4. An image processing method of multiplexing noise on multilevel image data to embed visible additional information with a noise-multiplexed distribution, comprising:

an input step of inputting, as the additional information, information representing whether or not to multiplex noise for each pixel;

a determination step of determining on the basis of the additional information whether a pixel of interest in the multilevel image data is located at a position where noise is to be multiplexed;

a specifying step of, when the pixel of interest is determined in the determination step to be located at the position where noise is to be multiplexed, specifying a bit region where noise is to be multiplexed on the basis of data of a neighboring region near the pixel of interest; and

a change step of reversibly changing bit information for the bit region of the pixel of interest specified in the specifying step.

5. An image processing method of removing visible additional information from multilevel image data in which noise is reversibly embedded to multiplex the visible additional information, comprising:

an input step of inputting, as the additional information, information representing whether or not to multiplex noise for each pixel;

a determination step of determining on the basis of the additional information whether a pixel of interest in the multilevel image data is located at a position where noise is multiplexed;

a specifying step of, when the pixel of interest is determined in the determination step to be located at the position where noise is multiplexed, specifying a bit region where noise is multiplexed on the basis of data of a neighboring region having undergone removal processing near the pixel of interest; and

a reconstruction step of performing conversion inverse to noise multiplexing to reconstruct a state of the bit region of the pixel of interest specified in the specifying step into a state before multiplexing.

6. A computer program functioning as an image processing apparatus which multiplexes noise on multilevel image data to embed visible additional information with a noise-multiplexed distribution, functioning as:

input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel;

determination means for determining on the basis of the additional information whether a pixel of interest in the multilevel image data is located at a position where noise is to be multiplexed;

specifying means for, when said determination means determines that the pixel of interest is located at the position where noise is to be multiplexed, specifying a bit region where noise is to be multiplexed on the basis of data of a neighboring region near the pixel of interest; and

change means for reversibly changing bit information for the bit region of the pixel of interest specified by said specifying means.

7. A computer-readable storage medium storing a computer program defined in claim 6.

8. A computer program functioning as an image processing apparatus which removes visible additional information from multilevel image data in which noise is reversibly embedded to multiplex the visible additional information, functioning as:

input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel;

determination means for determining on the basis of the additional information whether a pixel of interest in the multilevel image data is located at a position where noise is multiplexed;

specifying means for, when said determination means determines that the pixel of interest is located at the position where noise is multiplexed, specifying a bit region where noise is multiplexed on the basis of data of a neighboring region having undergone removal processing near the pixel of interest; and

reconstruction means for performing conversion inverse to noise multiplexing to reconstruct a state of the bit region of the pixel of interest specified by said specifying means into a state before multiplexing.

9. A computer-readable storage medium storing a computer program defined in claim 8.

10. An image processing apparatus which converts multilevel image data into frequency component data for each pixel block of a predetermined size to compression-code the multilevel image data, and multiplexes noise on the multilevel image to embed visible additional information with a noise-multiplexed distribution, comprising:

input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;

determination means for determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is to be multiplexed;

specifying means for, when said determination means determines that the pixel block of interest is located at the position where noise is to be multiplexed, specifying a bit region where noise is to be multiplexed in data constituting a converted low frequency component of the pixel block of interest on the basis of a reference region serving as a converted low frequency component of a neighboring pixel block near the pixel block of interest; and

change means for reversibly changing bit information for the bit region in the data of the low frequency component specified by said specifying means.

12. The apparatus according to claim 10, wherein the conversion into the frequency component includes orthogonal transform, and the low frequency component includes a DC component after orthogonal transform.

13. The apparatus according to claim 12, wherein the conversion into the frequency component includes wavelet transform, and the low frequency component includes data of a block of a low frequency component that is generated by wavelet transform a plurality of number of times.

14. The apparatus according to claim 10, further comprising means for setting information on an intensity for multiplexing noise, and

said specifying means specifies the bit region where noise is to be multiplexed at the low frequency component of the pixel block of interest on the basis of the set information on the intensity and the reference region.

11. An image processing apparatus which converts multilevel image data into frequency component data for each pixel block of a predetermined size to compression-code the multilevel image data, and multiplexes noise on the multilevel image to embed visible additional information with a noise-multiplexed distribution, comprising:

input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;

determination means for determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is to be multiplexed;

specifying means for, when said determination means determines that the pixel block of interest is located at the position where noise is to be multiplexed, specifying a bit region where noise is to be multiplexed in data constituting a low frequency component of the pixel block of interest on the basis of a reference region serving as a converted high frequency component of the pixel block of interest; and

change means for reversibly changing bit information for the bit region in the data of the low frequency component specified by said specifying means.

15. An image processing apparatus which removes visible additional information from multilevel image data that is compression-coded by reversibly embedding noise, multiplexing the visible additional information, and converting the data into frequency component data for each pixel block of a predetermined size, comprising:

input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;

determination means for determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is multiplexed;

specifying means for, when said determination means determines that the pixel block of interest is located at the position where noise is multiplexed, specifying a bit region where noise is multiplexed at a converted low frequency component of the pixel block of interest on the basis of a reference region serving as a converted low frequency component of a neighboring pixel block near the pixel block of interest; and

reconstruction means for performing conversion inverse to noise multiplexing to reconstruct a state of the bit region at the low frequency component of the pixel block of interest specified by said specifying means into a state before multiplexing.

16. An image processing apparatus which removes visible additional information from multilevel image data that is compression-coded by reversibly embedding noise, multiplexing the visible additional information, and converting the data into frequency component data for each pixel block of a predetermined size, comprising:

input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;

determination means for determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is multiplexed;

specifying means for, when said determination means determines that the pixel block of interest is located at the position where noise is multiplexed, specifying a bit region where noise is multiplexed at a low frequency component of the block of interest on the basis of a reference region serving as a converted high frequency component of the pixel block of interest; and

reconstruction means for performing conversion inverse to noise multiplexing to reconstruct a state of the bit region at the low frequency component of the pixel block of interest specified by said specifying means into a state before multiplexing.

17. An image processing method of converting multilevel image data into frequency component data for each pixel block of a predetermined size to compression-code the multilevel image data, and multiplexing noise on the multilevel image to embed visible additional information with a noise-multiplexed distribution, comprising:

an input step of inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;

a determination step of determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is to be multiplexed;

a specifying step of, when the pixel block of interest is determined in the determination step to be located at the position where noise is to be multiplexed, specifying a bit region where noise is to be multiplexed in data constituting a converted low frequency component of the pixel block of interest on the basis of a reference region serving as a converted low frequency component of a neighboring pixel block near the pixel block of interest; and

a change step of reversibly changing bit information for the bit region in the data of the low frequency component specified in the specifying step.

18. An image processing method of converting multilevel image data into frequency component data for each pixel block of a predetermined size to compression-code the multilevel image data, and multiplexing noise on the multilevel image to embed visible additional information with a noise-multiplexed distribution, comprising:

an input step of inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;

a determination step of determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is to be multiplexed;

a specifying step of, when the pixel block of interest is determined in the determination step to be located at the position where noise is to be multiplexed, specifying a bit region where noise is to be multiplexed in data constituting a low frequency component of the pixel block of interest on the basis of a reference region serving as a converted high frequency component of the pixel block of interest; and

a change step of reversibly changing bit information for the bit region in the data of the low frequency component specified in the specifying step.

19. An image processing method of removing visible additional information from multilevel image data that is compression-coded by reversibly embedding noise, multiplexing the visible additional information, and converting the data into frequency component data for each pixel block of a predetermined size, comprising:

an input step of inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;

a determination step of determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is multiplexed;

a specifying step of, when the pixel block of interest is determined in the determination step to be located at the position where noise is multiplexed, specifying a bit region where noise is multiplexed at a converted low frequency component of the pixel block of interest on the basis of a reference region serving as a converted low frequency component of a neighboring pixel block near the pixel block of interest; and

a reconstruction step of performing conversion inverse to noise multiplexing to reconstruct a state of the bit region at the low frequency component of the pixel block of interest specified in the specifying step into a state before multiplexing.

20. An image processing method of removing visible additional information from multilevel image data that is compression-coded by reversibly embedding noise, multiplexing the visible additional information, and converting the data into frequency component data for each pixel block of a predetermined size, comprising:

an input step of inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;

a determination step of determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is multiplexed;

a specifying step of, when the pixel block of interest is determined in the determination step to be located at the position where noise is multiplexed, specifying a bit region where noise is multiplexed at a low frequency component of the block of interest on the basis of a reference region serving as a converted high frequency component of the pixel block of interest; and

a reconstruction step of performing conversion inverse to noise multiplexing to reconstruct a state of the bit region at the low frequency component of the pixel block of interest specified in the specifying step into a state before multiplexing.

21. A computer program functioning as an image processing apparatus which converts multilevel image data into frequency component data for each pixel block of a predetermined size to compression-code the multilevel image data, and multiplexes noise on the multilevel image to embed visible additional information with a noise-multiplexed distribution, functioning as:

input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;

determination means for determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is to be multiplexed;

specifying means for, when said determination means determines that the pixel block of interest is located at the position where noise is to be multiplexed, specifying a bit region where noise is to be multiplexed in data constituting a converted low frequency component of the pixel block of interest on the basis of a reference region serving as a converted low frequency component of a neighboring pixel block near the pixel block of interest; and

change means for reversibly changing bit information for the bit region in the data of the low frequency component specified by said specifying means.

22. A computer-readable storage medium storing a computer program defined in claim 21.

23. A computer program functioning as an image processing apparatus which converts multilevel image data into frequency component data for each pixel block of a predetermined size to compression-code the multilevel image data, and multiplexes noise on the multilevel image to embed visible additional information with a noise-multiplexed distribution, functioning as:

input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;

determination means for determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is to be multiplexed;

specifying means for, when said determination means determines that the pixel block of interest is located at the position where noise is to be multiplexed, specifying a bit region where noise is to be multiplexed in data constituting a low frequency component of the pixel block of interest on the basis of a reference region serving as a converted high frequency component of the pixel block of interest; and

change means for reversibly changing bit information for the bit region in the data of the low frequency component specified by said specifying means.

24. A computer-readable storage medium storing a computer program defined in claim 23.

25. A computer program functioning as an image processing apparatus which removes visible additional information from multilevel image data that is compression-coded by reversibly embedding noise, multiplexing the visible additional information, and converting the data into frequency component data for each pixel block of a predetermined size, functioning as:

input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;

determination means for determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is multiplexed;

specifying means for, when said determination means determines that the pixel block of interest is located at the position where noise is multiplexed, specifying a bit region where noise is multiplexed at a converted low frequency component of the pixel block of interest on the basis of a reference region serving as a converted low frequency component of a neighboring pixel block near the pixel block of interest; and

reconstruction means for performing conversion inverse to noise multiplexing to reconstruct a state of the bit region at the low frequency component of the pixel block of interest specified by said specifying means into a state before multiplexing.

26. A computer-readable storage medium storing a computer program defined in claim 25.

27. A computer program functioning as an image processing apparatus which removes visible additional information from multilevel image data that is compression-coded by reversibly embedding noise, multiplexing the visible additional information, and converting the data into frequency component data for each pixel block of a predetermined size, functioning as:

input means for inputting, as the additional information, information representing whether or not to multiplex noise for each pixel block of the predetermined size;

determination means for determining on the basis of the input additional information whether a pixel block of interest is located at a position where noise is multiplexed;

specifying means for, when said determination means determines that the pixel block of interest is located at the position where noise is multiplexed, specifying a bit region where noise is multiplexed at a low frequency component of the block of interest on the basis of a reference region serving as a converted high frequency component of the pixel block of interest; and

reconstruction means for performing conversion inverse to noise multiplexing to reconstruct a state of the bit region at the low frequency component of the pixel block of interest specified by said specifying means into a state before multiplexing.

28. A computer-readable storage medium storing a computer program defined in claim 27.