Image data processing apparatus, image data processing method, and computer readable medium

• US 20040234139A1
• Filed: 04/15/2004
• Published: 11/25/2004
• Est. Priority Date: 05/20/2003
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Noda, Tsugio, Moroo, Jun
• Granted Patent: US 7,280,701 B2
• Time in Patent Office: Days
• US Class Current: 382/232
• CPC Class Codes: G06T 1/0021 Image watermarking
• 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

Abstract

To reduce the processing required to embed a code into image data and decode the code. The present invention includes a block dividing section 101 that divides original image data 10 into a plurality of blocks (M×N); an averaging section 103 that extracts each average density (characteristic amount) in a plurality of blocks; and an encoding section 106 that embeds a code C (a plurality of bits) into a plurality of blocks by relating one code (one bit out of the code C) to each pair of blocks mutually located in near position in the plurality of blocks based on a magnitude relation of the average density.

Claims

1. An image data processing apparatus comprising:

a dividing unit that divides image data into a plurality of blocks;

a characteristic amount extracting unit that extracts a characteristic amount from each of the blocks; and

an encoding unit that embeds a plurality of codes based on a magnitude relation of the characteristic amounts between each pair of blocks in proximity to each other in the plurality of blocks.

2. The image data processing apparatus according to claim 1, wherein the encoding unit changes at least one of the characteristic amounts of the pair of blocks so as to reverse the magnitude relation of the characteristic amounts between the pair of blocks when the magnitude relation does not coincide with a code to be embedded.

3. The image data processing apparatus according to claim 2, wherein the encoding unit does not change the characteristic amount when a difference between characteristic amounts of the pair of blocks exceeds a predetermined upper threshold.

4. The image data processing apparatus according to claim 1, wherein the encoding unit changes at least one of the characteristic amounts of the pair of blocks so as to arrange a difference between characteristic amounts of the pair of blocks to be equal to or larger than a predetermined lower threshold when the magnitude relation coincides with a code to be embedded and also when the difference is less than a lower threshold.

6. The image data processing apparatus according to claim 1, wherein the characteristic amount extracting unit extracts each characteristic amount from a portion of each block.

7. The image data processing apparatus according to claim 1, further comprising:

a cut-out unit that cuts out a yellow component from the blocks; and

wherein the encoding unit embeds a plurality of codes based on a magnitude relation of the characteristic amounts with regard to the yellow color components between each pair of blocks in the blocks.

8. The image data processing apparatus according to claim 1, wherein the encoding unit gives a cut-out mark for cutting-out an image area in which the codes are embedded.

9. The image data processing apparatus according to claim 1, wherein the characteristic amount is an average density.

10. The image data processing apparatus according to claim 1, wherein the characteristic amount is granularity, chroma, density barycenter, or variance.

11. The image data processing apparatus according to claim 1, wherein the encoding unit repeatedly embeds a plurality of codes.

5. An image data processing apparatus comprising:

a dividing unit that divides image data into a plurality of blocks;

an error-correction-coding code generating unit that encodes a code using an error correction coding to generate an error-correction-coding code;

a characteristic amount extracting unit that extracts a characteristic amount from each of the blocks; and

an encoding unit that embeds a plurality of error-correction-coding codes based on a magnitude relation of the characteristic amounts between each pair of blocks in proximity to each other in the plurality of blocks.

12. An image data decoding apparatus comprising:

a dividing unit that divides image data into a plurality of blocks;

a characteristic amount extracting unit that extracts a characteristic amount from each of the blocks; and

a decoding unit that decodes a plurality of codes based on a magnitude relation of the characteristic amounts between each pair of blocks in proximity to each other in the plurality of blocks.

13. An image data processing method comprising:

dividing image data into a plurality of blocks;

extracting a characteristic amount from each of the blocks; and

embedding a plurality of codes based on a magnitude relation of the characteristic amounts between each pair of blocks in proximity to each other in the plurality of blocks.

14. The image data processing method according to claim 13, further comprising:

changing at least one of the characteristic amounts of the pair of blocks so as to reverse the magnitude relation of the characteristic amounts between the pair of blocks when the magnitude relation does not coincide with a code to be embedded.

15. The image data processing method according to claim 14, further comprising:

not changing the characteristic amount when a difference between characteristic amounts of the pair of blocks exceeds a predetermined upper threshold.

16. The image data processing method according to claim 13, further comprising:

changing at least one of the characteristic amounts of the pair of blocks so as to arrange a difference between characteristic amounts of the pair of blocks to be equal to or larger than a predetermined lower threshold when the magnitude relation coincides with a code to be embedded and also when the difference is less than a lower threshold.

18. The image data processing method according to claim 13, further comprising:

extracting each characteristic amounts from a portion of each block.

19. The image data processing method according to claim 13, further comprising:

cutting out a yellow component from the blocks; and

embedding a plurality of codes based on a magnitude relation of the characteristic amounts with regard to the yellow color components between each pair of blocks in the blocks.

20. The image data processing method according to claim 13, further comprising:

giving a cut-out mark for cutting-out an image area in which the codes are embedded.

21. The image data processing method according to claim 13, wherein the characteristic amount is an average density.

22. The image data processing method according to claim 13, wherein the characteristic amount is granularity, chroma, density barycenter, or variance.

23. The image data processing method according to claim 13, wherein repeatedly embedding for a plurality of codes.

17. An image data processing method comprising:

dividing image data into a plurality of blocks;

encoding a code using an error correction coding to generate an error-correction-coding code;

extracting a characteristic amount from each of the blocks; and

embedding a plurality of error-correction-coding codes based on a magnitude relation of the characteristic amounts between each pair of blocks in proximity to each other in the plurality of blocks.

24. An image data decoding method for decoding codes in an image data comprising:

dividing image data into a plurality of blocks;

extracting a characteristic amount from each of the blocks; and

decoding a plurality of codes based on a magnitude relation of the characteristic amounts between each pair of blocks in proximity to each other in the plurality of blocks.

25. A computer-readable medium storing a program which, when executed by a computer, causes the computer to perform operations comprising:

dividing image data into a plurality of blocks;

extracting a characteristic amount from each of the blocks; and

embedding a plurality of based on a magnitude relation of the characteristic amounts between each pair of blocks in proximity to each other in the plurality of blocks.

26. The computer readable medium according to claim 25, further comprising:

changing at least one of the characteristic amounts of the pair of blocks so as to reverse the magnitude relation of the characteristic amounts between the pair of blocks when the magnitude relation does not coincide with a code to be embedded.

27. The computer readable medium according to claim 26, further comprising:

not changing the characteristic amount when a difference between characteristic amounts of the pair of blocks exceeds a predetermined upper threshold.

28. The computer readable medium according to claim 25, further comprising:

changing at least one of the characteristic amounts of the pair of blocks so as to arrange a difference between characteristic amounts of the pair of blocks to be equal to or larger than a predetermined lower threshold when the magnitude relation coincides with a code to be embedded and also when the difference is less than a lower threshold.

30. The computer readable medium according to claim 25, further comprising:

extracting each characteristic amounts from a portion of each block.

31. The computer readable medium according to claim 25, further comprising:

cutting out a yellow component from the blocks; and

embedding a plurality of codes based on a magnitude relation of the characteristic amounts with regard to the yellow color components between each pair of blocks in the blocks.

32. The computer readable medium according to claim 25, further comprising:

giving a cut-out mark for cutting-out an image area in which the codes are embedded.

33. The computer readable medium according to claim 25, wherein the characteristic amount is an average density.

34. The computer readable medium according to claim 25, wherein the characteristic amount is granularity, chroma, density barycenter, or variance.

35. The computer readable medium according to claim 25, wherein repeatedly embedding for a plurality of codes.

29. A computer-readable medium storing a program which, when executed by a computer, causes the computer to perform operations comprising:

dividing image data into a plurality of blocks;

encoding a code using an error correction coding to generate an error-correction-coding code;

extracting a characteristic amount from each of the blocks; and

embedding a plurality of error-correction-coding codes based on a magnitude relation of the characteristic amounts between each pair of blocks in proximity to each other in the plurality of blocks.

36. A computer readable medium storing a program which, when executed by a computer, causes the computer to perform decoding operations for decoding codes in an image data comprising:

dividing image data into a plurality of blocks;

extracting a characteristic amount from each of the blocks; and

decoding a plurality of codes based on a magnitude relation of the characteristic amounts between each pair of blocks in proximity to each other in the plurality of blocks.