Method and system for embedding information into contents

• US 20020076086A1
• Filed: 02/12/2002
• Published: 06/20/2002
• Est. Priority Date: 09/03/1997
• Status: Active Grant

• Current Assignee: Maxell, Ltd.
• Original Assignee: Akira Maeda, Hiroshi Yoshiura, Isao Echizen, Junichi Taguchi, Takao Arai, Toshifumi Takeuchi
• Inventors: Maeda, Akira, Taguchi, Junichi, Echizen, Isao, Yoshiura, Hiroshi, Takeuchi, Toshifumi, Arai, Takao
• Granted Patent: US 6,826,291 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 1/005 Robust watermarking, e.g. average attack or collusion attack resistant
• 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: 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 1/32229 with selective or adaptive application of the additional information, e.g. in selected regions of the image H04N1/32213 takes precedence
• CPC Class Codes: H04N 1/32251 in multilevel data, e.g. greyscale or continuous tone data
• CPC Class Codes: H04N 1/32288 Multiple embedding, e.g. cocktail embedding, or redundant embedding, e.g. repeating the additional information at a plurality of locations in the image
• CPC Class Codes: H04N 19/00 Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
• CPC Class Codes: H04N 19/467 characterised by the embedded information being invisible, e.g. watermarking
• CPC Class Codes: H04N 21/23892 involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level
• CPC Class Codes: H04N 21/8358 involving watermark protecting executable software by watermarking G06F21/16; image watermarking in general G06T1/0021; watermarks inserted in still images for transmission purposes H04N1/32144; inserting watermarks during video coding H04N19/467

Abstract

A method of embedding information into contents includes a changeable range calculating step of obtaining a range where value change of the contents is imperceptible to the human being and a step of embedding information by changing the values of the contents within the changeable range.

Claims

1. An image processing method of embedding information into an image by changing a value of a predetermined pixel included in the image, comprising the steps of:

(1) determining a direction of a vector, wherein pixels along said direction satisfies a predetermined status, using said predetermined pixel and pixels surrounding said predetermined pixel;

(2) performing image processing on said predetermined pixel and pixels along said direction; and

(3) obtaining a difference, as to said predetermined pixel, between a value before said image processing and a value after said image processing.

2. An image processing method according to claim 1, further comprising the steps of:

(4) setting a plurality of predetermined pixels;

(5) performing steps (1) to (3) on each of said plurality of predetermined pixels set in step (4); and

(6) determining a value of change amount of each of said predetermined pixels based on differences obtained in step (5) and a predetermined value.

3. An image processing method according to claim 2, wherein said method satisfies at least one of conditions:

(a) that the determination in step (1) is performed based on respective degrees of change of values along a direction of a vectors passing through said predetermined pixel,

(b) that the image processing of step (2) is a smoothing process, and

(c) that a change amount of step (6) is determined to be less than an upper limit value set as said predetermined value.

4. An image processing method according to claim 2, further comprising the step of:

(7) determining a value of a change amount of each predetermined pixel again such that a calculation using the plurality of change amounts determined in the step (6) satisfies a predetermined condition.

5. An image processing method according to claim 4, wherein the calculation is addition.

6. An image processing method according to claim 5, wherein a pixel value is an intensity of the pixel.

7. An image processing method according to claim 2, further comprising the steps of:

(7) performing steps (4) to (6) for respective bits in information to be embedded;

(8) changing pixel values based on the determined change amounts; and

(9) outputting the image in which pixel values are changed.

16. An image processing method according to claim 3, wherein the predetermined status in said (1) step is that the change of pixel values along a direction of a vector passing through said predetermined pixel is the smallest among changes of pixel values along directions of vectors passing through said predetermined pixel.

18. An image processing method according to claim 1, further comprising a step of:

(11) determining whether the value of said predetermined pixel is to be changed or not in accordance with the difference obtained in step (3).

19. An image processing method according to claim 2, further comprising a step of:

(12) selecting the pixel wherein the value of the pixel is to be changed from said plurality of predetermined pixels using the change amounts obtained in step (6).

8. A program for embedding information into an image by changing a value of predetermined pixel included in the image, said program executable by a computer and including codes for causing a computer to execute the steps of:

(1) determining a direction of a vector based on a degree of change of values in a predetermined pixel and pixels surrounding said predetermined pixel;

(2) performing image processing along said direction; and

(3) obtaining a difference, as to said predetermined pixel, between a value before said image processing and a value after said image processing.

9. A storage device readable by a computer, embodying a program of instructions executable by the computer to perform image processing for embedding information into an image, said program when executed causes the computer to perform the steps of:

(1) determining a direction of a vector based on a degree of change of values in a predelermined pixel and pixels surrounding said predetermined pixel;

(2) performing image processing along said direction; and

(3) obtaining a difference, as to said predetermined pixel, between a value before said image processing and a value after said image processing.

10. A storage device according to claim 9, wherein said program when executed further causes the computer to perform the steps of:

(4) setting a plurality of predetermined pixels;

(5) performing steps (1) to (3) on each of said plurality of predetermined pixels set in step (4); and

(6) determining a value of a change amount of each of said predetermined pixels based on differences obtained in step (5) and a predetermined value.

11. A storage device according to claim 10, wherein said program when executed satisfies at least one of conditions:

(a) that the determination in step (1) is performed based on degrees of change of said values along a direction of a vector passing through said predetermined pixel,

(b) that said image processing of step (2) is a smoothing process; and

(c) that the change amount of step (6) is determined to be less than an upper limit value set as a predetermined value.

12. A storage device according to claim 10, wherein said program when executed further causes the computer to perform the step of:

(7) determining change amount of value of the predetermined pixel again such that calculation using the plurality of determined change amounts in the step (6) satisfies a predetermined condition.

13. A storage device according to claim 12, wherein the calculation is addition.

14. A storage device according to claim 13, wherein the pixel value is an intensity of the pixel.

15. A storage device according to claim 10, wherein said program when executed further causes the computer to perform the steps of:

(7) performing steps (4) to (6) for respective bits in information to be embedded;

(8) changing pixel values based on the determined change amounts; and

(9) outputting the image in which pixel values are changed.

17. An image processing method according to claim 16, wherein said pixel value is an intensity value.

20. An article of manufacture comprising:

a computer usable medium having a computer readable program code which includes a network-distributed program, said computer readable program code being embodied in said computer usable medium for causing image processing for embedding information into an image, said computer readable program code in said article of manufacture comprising;

computer readable program code for determining a direction of a vector based on a degree of change of values in a predetermined pixel and pixels surrounding said predetermined pixel,

computer readable program code for performing image processing along said direction, and

computer readable program code for obtaining a difference, as to said predetermined pixel, between a value before said image processing and a value after said image processing.

21. An article of manufacture according to claim 20, wherein said computer readable program code in said computer usable medium further comprises:

computer readable program code for setting a plurality of predetermined pixels;

computer readable program code for performing said determining a direction, said image processing and said obtaining operations on each of said plurality of predetermined pixels set in said setting operation; and

computer readable program code for determining a value of a change amount of each of said predetermined pixels based on differences obtained in said operation of performing said determining a direction, said image processing and obtaining operations and a predetermined value.

22. An article of manufacture according to claim 21, wherein said computer readable program code when operated satisfies at least one of conditions:

(a) that the determination in said determining a direction of a vector operation is performed based on degrees of change of said values along a direction of a vector passing through said predetermined pixel;

(b) that said performing image processing operation is a smoothing process; and

(c) that the change amount is determined by said determining a value of a change amount operation to be less than an upper limit value set as a predetermined value.

23. An article of manufacture according to claim 21, wherein said computer readable program code in said computer usable medium further comprises:

computer readable program code for determining a change amount of value of the predetermined pixel again such that calculation using the plurality of determined change amounts in determining a value operation satisfies a predetermined condition.

24. An article of manufacture according to claim 23, wherein the calculation is addition.

25. An article of manufacture according to claim 24, wherein the pixel value is an intensity of the pixel.

26. An article of manufacture according to claim 21, wherein said computer readable program code in said computer usable medium further comprises:

computer readable program code for performing said setting, said determining a direction, said image processing, said obtaining and said determining a value operations for respective bits in information to be embedded;

computer readable program code for changing pixel values based on the determined change amounts; and

computer readable program code for outputting the image in which pixel values are changed.