Method for embedding and reading watermark-information in digital form, and apparatus thereof

• US 6,185,312 B1
• Filed: 01/27/1998
• Issued: 02/06/2001
• Est. Priority Date: 01/28/1997
• Status: Expired due to Fees

• Current Assignee: Nippon Telegraph and Telephone Corporation
• Original Assignee: Nippon Telegraph and Telephone Corporation
• Inventors: Takashima, Yoichi, Ogawa, Hiroshi, Nakamura, Takao
• Primary Examiner(s): Lee, Thomas D.
• Assistant Examiner(s): Chen, Wenpeng
• Application Number:
  US09/014,159
• Time in Patent Office: 1,106 Days
• Field of Search: 382/232, 382/100, 382/115, 382/284, 382/237, 382/251, 380/4, 380/54, 380/23, 380/3, 380/28, 380/55, 283/113, 283/17, 283/73
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0057 Compression invariant watermarking
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 2201/0052 Embedding of the watermark in the frequency domain
• CPC Class Codes: G06T 2201/0061 Embedding of the watermark in each block of the image, e.g. segmented watermarking
• CPC Class Codes: H04N 1/32154 Transform domain methods H04N1/32309 takes precedence
• 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 1/32277 Compression
• 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
• CPC Class Codes: H04N 2201/3233 of authentication information, e.g. digital signature, watermark
• CPC Class Codes: H04N 2201/327 which are undetectable to the naked eye, e.g. embedded codes

Abstract

An apparatus for embedding information comprises: a blocking step for dividing data to be processed into blocks; an orthogonal transform step for obtaining coefficients by carrying out orthogonal transformation for each block; an embedding coefficient selecting step for determining coefficients in which the watermark-information will be embedded by using a random sequence which is generated by initial value; an information embedding step for sequentially embedding the watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and an inverse orthogonal transform step for carrying out inverse orthogonal transformation for modified coefficients to form block in which the watermark-information is embedded, as well as combining the divided blocks and reconstructing the original form.

Claims

1. A method of embedding information comprising:

a blocking step for dividing original data into blocks;

an orthogonal transform step for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting step for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding step for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform step for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form,

wherein in said orthogonal transform step said orthogonal transform is a three dimensional orthogonal transform, and in said inverse orthogonal transform step, said inverse orthogonal transform is a three dimensional inverse orthogonal transform,

in said information embedding step, the entropy of the data value of the block to be processed is utilized for determining said predetermined value for quantization; and

in said inverse orthogonal transform step, when the orthogonal transform coefficient obtained by said information embedding step is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

2. A method of embedding information comprising:

a blocking step for dividing original data into blocks;

an orthogonal transform step for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting step for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding step for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform step for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form,

wherein in said orthogonal transform step said orthogonal transform is a three dimensional orthogonal transform, and in said inverse orthogonal transform step, said inverse orthogonal transform is a three dimensional inverse orthogonal transform,

in said orthogonal transform step, the block from said blocking step is down-sampled so that the block size is smaller, after which the down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient,

in said inverse orthogonal transform step, after inverse orthogonally transforming the orthogonal transform coefficients obtained by said information embedding step, up sampling is performed so as to give a block of the size prior to down-sampling by said blocking step,

in said information embedding step, the entropy of the data value of the block to be processed is utilized for determining said predetermined value for quantization; and

in said inverse orthogonal transform step, when the orthogonal transform coefficient obtained by said information embedding step is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

3. A method of embedding information comprising:

a blocking step for dividing original data into blocks;

an orthogonal transform step for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting step for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding step for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform step for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form,

wherein in said orthogonal transform step said orthogonal transform is a three dimensional orthogonal transform, and in said inverse orthogonal transform step, said inverse orthogonal transform is a three dimensional inverse orthogonal transform,

in said orthogonal transform step, the block from said blocking step is down-sampled so that the block size is smaller, after which the down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient,

in said inverse orthogonal transform step, after inverse orthogonally transforming the orthogonal transform coefficients obtained by said information embedding step, up sampling is performed so as to give a block of the size prior to down-sampling by said blocking step,

in said information embedding step, a value of a low frequency domain in the orthogonal transform coefficient obtained by said orthogonal transform step is utilized for normalizing the orthogonal transform coefficients; and

in said inverse orthogonal transform step, when the orthogonal transform coefficient obtained by said information embedding step is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

4. A method of embedding information comprising:

a blocking step for dividing original data into blocks;

an orthogonal transform step for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting step for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding step for sequentially embedding watermark-information, which has arbitrarm length of bits by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform step for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form,

wherein in said orthogonal transform step said orthogonal transform is a three dimensional orthogonal transform, and in said inverse orthogonal transform step, said inverse orthogonal transform is a three dimensional inverse orthogonal transform,

in said information embedding step, a value of a low frequency domain in the orthogonal transform coefficient obtained by said orthogonal transform step is utilized for normalizing the orthogonal transform coefficients; and

in said inverse orthogonal transform step, when the orthogonal transform coefficient obtained by said information embedding step is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

5. A method of embedding information comprising:

a blocking step for dividing original data into blocks;

an orthogonal transform step for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting step for determining coefficients in which the watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding step for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform step for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form wherein

in said information embedding step, the entropy of the data value of the block to be processed is utilized for determining said predetermined value for quantization; and

in said inverse orthogonal transform step, when the orthogonal transform coefficient obtained by said information embedding step is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

6. A method of reading information from data embedded with information by the method according to claim 5 comprising:

a blocking step for dividing said data into blocks;

an embedding coefficient selecting step for determining coefficients from which the watermark-information will be read by using a random sequence which is generated by the initial value which is used at the time of embedding the watermark-information;

an object coefficient computing step for obtaining the coefficients by carrying out orthogonal transformation for each block; and

a bit reading step for sequentially reading each bit of the embedded watermark-information and outputting the read watermark-information wherein

in said bit reading step, the entropy of the data value of the block to be processed is utilized for determining said predetermined value for quantization.

7. A method of reading information according to claim 6, wherein in said object coefficient computing step,

said orthogonal transform is an orthogonal transform of a dimension corresponding to the dimension number of the orthogonal transform used at the time of information embedding.

8. A method of reading information according to claim 7, wherein in the case where down-sampling of the block is carried out at the time of information embedding,

then in said object coefficient computing step, an orthogonal transform coefficient is obtained from the block which is down-sampled so that the block obtained from said blocking step is the same.

9. A method of reading information according to claim 6, wherein in the case where down-sampling of the block is carried out at the time of information embedding, then in said object coefficient computing step, an orthogonal transform coefficient is obtained from the block which is down-sampled so that the block obtained from said blocking step is the same.

10. A method of embedding information according to claim 5, wherein in said orthogonal transform step said orthogonal transform is a two dimensional orthogonal transform, and in said inverse orthogonal transform step, said inverse orthogonal transform is a two dimensional inverse orthogonal transform.

11. A method of embedding information according to claim 10, wherein in said orthogonal transform step,

the block from said blocking step is down-sampled so that the block size is smaller, after which the down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient, and

in said inverse orthogonal transform step, after inverse orthogonally transforming the orthogonal transform coefficients obtained by said information embedding step, up sampling is performed so as to give a block of the size prior to down-sampling by said blocking step.

12. A method of embedding information according to claim 5, wherein in said orthogonal transform step,

the block from said blocking step is down-sampled so that the block size is smaller, after which the down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient, and

in said inverse orthogonal transform step, after inverse orthogonally transforming the orthogonal transform coefficients obtained by said information embedding step, up sampling is performed so as to give a block of the size prior to down-sampling by said blocking step.

42. An apparatus for reading information from data embedded with information by the method according to claim 5 comprising:

a blocking section for dividing said data into blocks;

an embedding coefficient selecting section for determining coefficients from which the watermark-information will be read by using a random sequence which is generated by the initial value which is used at the time of embedding the watermark-information;

an object coefficient computing section for obtaining the coefficients by carrying out orthogonal transformation for each block; and

a bit reading section for sequentially reading each bit of the embedded watermark-information and outputting the read watermark-information wherein in said bit reading section, the entropy of the data value of the block to be processed is utilized for determining said predetermined value for quantization.

43. An apparatus for reading information according to claim 42, wherein in said object coefficient computing section,

said orthogonal transform is an orthogonal transform of a dimension corresponding to the dimension number of the orthogonal transform used at the time of information embedding.

44. An apparatus for reading information according to claim 43, wherein in the case where down-sampling of the block is carried out at the time of information embedding,

then in said object coefficient computing section, an orthogonal transform coefficient is obtained from the block which is down-sampled so that the block obtained from said blocking section is the same.

45. An apparatus for reading information according to claim 42, wherein in the case where down-sampling of the block is carried out at the time of information embedding, then in said object coefficient computing section, an orthogonal transform coefficient is obtained from the block which is down-sampled so that the block obtained from said blocking section is the same.

67. A recording medium which can be read by a computer and on which is recorded an information reading program for reading information from data embedded with information by the method according to claim 5 comprising:

a blocking function for dividing said data into blocks;

an embedding coefficient selecting function for determining coefficients from which the watermark-information will be read by using a random sequence which is generated by the initial value which is used at the time of embedding the watermark-information;

an object coefficient computing function for obtaining the coefficients by carrying out orthogonal transformation for each block; and

a bit reading function for sequentially reading each bit of the embedded watermark-information and outputting the read watermark-information wherein in said bit reading function, the entropy of the data value of the block to be processed is utilized for determining said predetermined value for quantization.

68. A recording medium according to claim 67, wherein in said object coefficient computing function,

said orthogonal transform is an orthogonal transform of a dimension corresponding to the dimension number of the orthogonal transform used at the time of information embedding.

69. A reading medium according to claim 68, wherein in the case where down-sampling of the block is carried out at the time of information embedding,

then in said object coefficient computing function, an orthogonal transform coefficient is obtained from the block which is down-sampled so that the block obtained from said blocking function is the same.

70. A recording medium according to claim 67, wherein in the case where down-sampling of the block is carried out at the time of information embedding, then in said object coefficient computing function, an orthogonal transform coefficient is obtained from the block which is down-sampled so that the block obtained from said blocking function is the same.

13. A method of embedding information comprising:

a blocking step for dividing original data into blocks;

an orthogonal transform step for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting step for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding step for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform step for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form wherein

in said information embedding step, a value of a low frequency domain in the orthogonal transform coefficient obtained by said orthogonal transform step is utilized for normalizing the orthogonal transform coefficients; and

in said inverse orthogonal transform step, when the orthogonal transform coefficient obtained by said information embedding step is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

14. A method of reading information from data embedded with information by the method according to claim 13 comprising:

a blocking step for dividing said data into blocks;

an embedding coefficient selecting step for determining coefficients from which the watermark-information will be read by using a random sequence which is generated by the initial value which is used at the time of embedding the watermark-information;

an object coefficient computing step for obtaining the coefficients by carrying out orthogonal transformation for each block; and

a bit reading step for sequentially reading each bit of the embedded watermark-information and outputting the read watermark-information wherein

in said bit reading step, the orthogonal transform coefficient of the low frequency domain in the orthogonal transform coefficients is utilized for normalizing the orthogonal transform coefficients.

15. A method of reading information according to claim 14, wherein in said object coefficient computing step,

said orthogonal transform is an orthogonal transform of a dimension corresponding to the dimension number of the orthogonal transform used at the time of information embedding.

16. A method of reading information according to claim 15, wherein in the case where down-sampling of the block is carried out at the time of information embedding,

then in said object coefficient computing step, an orthogonal transform coefficient is obtained from the block which is down-sampled so that the block obtained from said blocking step is the same.

17. A method of reading information according to claim 14, wherein in the case where down-sampling of the block is carried out at the time of information embedding,

then in said object coefficient computing step, an orthogonal transform coefficient is obtained from the block which is down-sampled so that the block obtained from said blocking step is the same.

18. A method of embedding information according to claim 13, wherein in said orthogonal transform step said orthogonal transform is a two dimensional orthogonal transform, and in said inverse orthogonal transform step, said inverse orthogonal transform is a two dimensional inverse orthogonal transform.

19. A method of embedding information according to claim 18, wherein in said orthogonal transform step,

the block from said blocking step is down-sampled so that the block size is smaller, after which the down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient, and

in said inverse orthogonal transform step, after inverse orthogonally transforming the orthogonal transform coefficients obtained by said information embedding step, up sampling is performed so as to give a block of the size prior to down-sampling by said blocking step.

20. A method of embedding information according to claim 13, wherein in said orthogonal transform step,

the block from said blocking step is down-sampled so that the block size is smaller, after which the down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient, and

in said inverse orthogonal transform step, after inverse orthogonally transforming the orthogonal transform coefficients obtained by said information embedding step, up sampling is performed so as to give a block of the size prior to down-sampling by said blocking step.

21. A method of embedding information according to claim 13, wherein said information embedding step comprises the steps of:

calculating a mean value of coefficients of the low frequency domain in the orthogonal transform coefficient obtained by said orthogonal transform step;

obtaining a ratio between the mean value and a prescribed fixed value;

normalizing all the orthogonal transform coefficient by multiplying by the ratio;

embedding the watermark-information into the normalized coefficients; and

inverse-normalizing the information-embedded coefficients by dividing by the ratio.

22. A method of reading information according to claim 14, wherein, when the watermark-information was embedded by the method of claim 21, said bit reading step comprises the steps of:

calculating mean value of coefficients of the low frequency domain in the orthogonal transform coefficient obtained by said object coefficient computing step;

obtaining a ratio between the mean value and a prescribed fixed value;

normalizing all the orthogonal transform coefficient by multiplying by the ratio; and

reading each bit of the embedded watermark-information from the normalized coefficients.

46. An apparatus for reading information from data embedded with information by the method according to claim 13 comprising:

a blocking section for dividing said data into blocks;

an embedding coefficient selecting section for determining coefficients from which the watermark-information will be read by using a random sequence which is generated by the initial value which is used at the time of embedding the watermark-information;

an object coefficient computing section for obtaining the coefficients by carrying out orthogonal transformation for each block; and

a bit reading section for sequentially reading each bit of the embedded watermark-information and outputting the read watermark-information wherein in said bit reading section, the orthogonal transform coefficient of the low frequency domain in the orthogonal transform coefficients is utilized for normalizing the orthogonal transform coefficients.

47. An apparatus for reading information according to claim 46, wherein in said object coefficient computing section,

said orthogonal transform is an orthogonal transform of a dimension corresponding to the dimension number of the orthogonal transform used at the time of information embedding.

48. An apparatus for reading information according to claim 47, wherein in the case where down-sampling of the block is carried out at the time of information embedding,

then in said object coefficient computing section, an orthogonal transform coefficient is obtained from the block which is down-sampled so that the block obtained from said blocking section is the same.

50. An apparatus for reading information according to claim 46, wherein in the case where down-sampling of the block is carried out at the time of information embedding,

then in said object coefficient computing section, an orthogonal transform coefficient is obtained from the block which is down-sampled so that the block obtained from said blocking section is the same.

71. A reading medium which can be read by a computer and on which is recorded an information reading program for reading from data embedded with information by the method according to claim 13 comprising:

a blocking function for dividing said data into blocks;

an embedding coefficient selecting function for determining coefficients from which the watermark-information will be read by using a random sequence which is generated by the initial value which is used at the time of embedding the watermark-information;

an object coefficient computing function for obtaining the coefficients by carrying out orthogonal transformation for each block; and

a bit reading function for sequentially reading each bit of the embedded watermark-information and outputting the read watermark-information wherein in said bit reading function, the orthogonal transform coefficient of the low frequency domain in the orthogonal transform coefficients is utilized for normalizing the orthogonal transform coefficients.

72. A recording medium according to claim 71, wherein in said object coefficient computing function,

said orthogonal transform is an orthogonal transform of a dimension corresponding to the dimension number of the orthogonal transform used at the time of information embedding.

73. A recording medium according to claim 72, wherein in the case where down-sampling of the block is carried out at the time of information embedding,

then in said object coefficient computing function, an orthogonal transform coefficient is obtained from the block which is down-sampled so that the block obtained from said blocking function is the same.

74. A recording medium according to claim 71, wherein in the case where down-sampling of the block is carried out at the time of information embedding,

then in said object coefficient computing function, an orthogonal transform coefficient is obtained from the block which is down-sampled so that the block obtained from said blocking function is the same.

23. A method of embedding information comprising:

a blocking step for dividing original data into blocks;

an orthogonal transform step for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting step for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding step for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform step for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form wherein in said inverse orthogonal transform step,

when the orthogonal transform coefficient obtained by said information embedding step is inverse orthogonal transformed, processing is further performed by utilizing two pixel matrixes, one pixel matrix is obtained by;

changing a DC component value of the orthogonal transform coefficient obtained by said information embedding step to the minimum value of a defined range;

changing all values of the embedded coefficients to 0; and

inverse-orthogonal-transforming the changed matrix; and

the other pixel matrix is obtained by;

changing a DC component of the orthogonal transform coefficient obtained by said information embedding step to 0;

changing all values of the non-embedded coefficients to 0; and

inverse-orthogonal-transforming the changed matrix;

so that the value after inverse orthogonal transform does not exceed a defined range of pixel value of the original data form.

24. A method of embedding information according to claim 23, wherein in said inverse orthogonal transform step,

the processing so that the value after inverse orthogonal transform does not exceed a defined range, uses the data obtained by said inverse orthogonal transform, and the whole data is reduced with the mean value of the data as the center.

25. A method of embedding information comprising:

a blocking step for dividing original data into blocks;

an orthogonal transform step for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting step for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding step for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform step for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form wherein in said inverse orthogonal transform step,

when the orthogonal transform coefficient obtained by said information embedding step is inverse orthogonal transformed, processing is further performed so that the value after inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

26. An apparatus for embedding information comprising:

a blocking section for dividing original data into blocks;

an orthogonal transform section for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting section for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding section for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform section for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form,

wherein in said orthogonal transform section said orthogonal transform is a three dimensional orthogonal transform, and in said inverse orthogonal transform section, said inverse orthogonal transform is a three dimensional inverse orthogonal transform,

in said orthogonal transform section, the block from said blocking section is down-sampled so that the block size is smaller, after which he down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient,

in said inverse orthogonal transform section, after inverse orthogonally transforming the orthogonal transform coefficients obtained in said information embedding section, up sampling is performed so as to give a block of the size prior to down-sampling in said blocking section,

in said information embedding section, the entropy of the data value of the block to be processed is utilized for determining said predetermined value for quantization; and

in said inverse orthogonal transform section, when the orthogonal transform coefficient obtained in said information embedding section is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

27. An apparatus for embedding information comprising:

a blocking section for dividing original data into blocks;

an orthogonal transform section for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting section for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding section for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform section for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form,

wherein in said orthogonal transform section said orthogonal transform is a three dimensional orthogonal transform, and in said inverse orthogonal transform section, said inverse orthogonal transform is a three dimensional inverse orthogonal transform,

in said orthogonal transform section, the block from said blocking section is down-sampled so that the block size is smaller, after which the down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient,

in said inverse orthogonal transform section, after inverse orthogonally transforming the orthogonal transform coefficients obtained in said information embedding section, up sampling is performed so as to give a block of the size prior to down-sampling in said blocking section,

in said information embedding section, a value of a low frequency domain in the orthogonal transform coefficient obtained in said orthogonal transform section is utilized for normalizing the orthogonal transform coefficients; and

in said inverse orthogonal transform section, when the orthogonal transform coefficient obtained in said information embedding section is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

28. An apparatus for embedding information comprising:

a blocking section for dividing original data into blocks;

an orthogonal transform section for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting section for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding section for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform section for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form,

wherein in said orthogonal transform section said orthogonal transform is a three dimensional orthogonal transform, and in said inverse orthogonal transform section, said inverse orthogonal transform is a three dimensional inverse orthogonal transform,

in said information embedding section, the entropy of the data value of the block to be processed is utilized for determining said predetermined value for quantization; and

in said inverse orthogonal transform section, when the orthogonal transform coefficient obtained in said information embedding section is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

29. An apparatus for embedding information comprising:

a blocking section for dividing original data into blocks;

an orthogonal transform section for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting section for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding section for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform section for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form,

wherein in said orthogonal transform section said orthogonal transform is a three dimensional orthogonal transform, and in said inverse orthogonal transform section, said inverse orthogonal transform is a three dimensional inverse orthogonal transform,

in said information embedding section, a value of a low frequency domain in the orthogonal transform coefficient obtained in said orthogonal transform section is utilized for normalizing the orthogonal transform coefficients; and

in said inverse orthogonal transform section, when the orthogonal transform coefficient obtained in said information embedding section is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

30. An apparatus for embedding information comprising:

a blocking section for dividing original data into blocks;

an orthogonal transform section for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting section for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding section for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform section for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form wherein

in said information embedding section, the entropy of the data value of the block to be processed is utilized for determining said predetermined value for quantization; and

in said inverse orthogonal transform section, when the orthogonal transform coefficient obtained in said information embedding section is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

31. An apparatus for embedding information according to claim 30, wherein in said orthogonal transform section said orthogonal transform is a two dimensional orthogonal transform, and in said inverse orthogonal transform section, said inverse orthogonal transform is a two dimensional inverse orthogonal transform.

32. An apparatus for embedding information according to claim 31, wherein in said orthogonal transform section,

the block from said blocking section is down-sampled so that the block size is smaller, after which the down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient, and

in said inverse orthogonal transform section, after inverse orthogonally transforming the orthogonal transform coefficients obtained by said information embedding step, up sampling is performed so as to give a block of the size prior to down-sampling in said blocking section.

33. An apparatus for embedding information according to claim 30, wherein in said orthogonal transform section,

the block from said blocking section is down-sampled so that the block size is smaller, after which the down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient, and

in said inverse orthogonal transform section, after inverse orthogonally transforming the orthogonal transform coefficients obtained in said information embedding section, up sampling is performed so as to give a block of the size prior to down-sampling in said blocking section.

34. An apparatus for embedding information comprising:

a blocking section for dividing original data into blocks;

an orthogonal transform section for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting section for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding section for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform section for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form wherein

in said information embedding section, a value of a low frequency domain in the orthogonal transform coefficient obtained in said orthogonal transform section is utilized for normalizing the orthogonal transform coefficients; and

in said inverse orthogonal transform section, when the orthogonal transform coefficient obtained in said information embedding step is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

35. An apparatus for embedding information according to claim 34, wherein in said orthogonal transform section said orthogonal transform is a two dimensional orthogonal transform, and in said inverse orthogonal transform section, said inverse orthogonal transform is a two dimensional inverse orthogonal transform.

36. An apparatus for embedding information according to claim 35, wherein in said orthogonal transform section,

the block from said blocking section is down-sampled so that the block size is smaller, after which the down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient, and

in said inverse orthogonal transform section, after inverse orthogonally transforming the orthogonal transform coefficients obtained in said information embedding section, up sampling is performed so as to give a block of the size prior to down-sampling by said blocking section.

37. An apparatus for embedding information according to claim 34, wherein in said orthogonal transform section,

the block from said blocking section is down-sampled so that the block size is smaller, after which the down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient, and

in said inverse orthogonal transform section, after inverse orthogonally transforming the orthogonal transform coefficients obtained in said nation embedding section, up sampling is performed so as to give a block of the size prior to down-sampling in said blocking section.

38. An apparatus for embedding information according to claim 34, wherein said information embedding section comprises the steps of:

means for calculating a mean value of coefficients of the low frequency domain in the orthogonal transform coefficient obtained in said orthogonal transform section;

means for obtaining a ratio between the mean value and a prescribed fixed value;

means for normalizing all the orthogonal transform coefficient by multiplying by the ratio;

means for embedding the watermark-information into the normalized coefficients; and

means for inverse-normalizing the information-embedded coefficients by dividing by the ratio.

49. An apparatus for reading information according to claim 46, wherein, when the watermark-information was embedded according to claim 38, said bit reading section comprises:

means for calculating mean value of coefficients of the low frequency domain in the orthogonal transform coefficient obtained in said object coefficient computing section;

means for obtaining a ratio between the mean value and a prescribed fixed value;

means for normalizing all the orthogonal transform coefficient by multiplying by the ratio; and

means for reading each bit of the embedded watermark-information from the normalized coefficients.

39. An apparatus for embedding information comprising:

a blocking section for dividing original data into blocks;

an orthogonal transform section for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting section for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding section for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform section for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form wherein in said inverse orthogonal transform step,

when the orthogonal transform coefficient obtained in said information embedding section is inverse orthogonal transformed, processing is further performed by utilizing two pixel matrixes, one pixel matrix is obtained by;

changing a DC component value of the orthogonal transform coefficient obtained in said information embedding section to the minimum value of a defined range;

changing all values of the embedded coefficients to 0; and

inverse-orthogonal-transforming the changed matrix; and

the other pixel matrix is obtained by;

changing a DC component of the orthogonal transform coefficient obtained by said information embedding step to 0;

changing all values of the non-embedded coefficients to 0; and

inverse-orthogonal-transforming the changed matrix;

so that the value after inverse orthogonal transform does not exceed a defined range of pixel value of the original data form.

40. An apparatus for embedding information according to claim 39, wherein in said inverse orthogonal transform section,

the processing so that the value after inverse orthogonal transform does not exceed a defined range, uses the data obtained by said inverse orthogonal transform, and the whole data is reduced with the mean value of the data as the center.

41. An apparatus for embedding information comprising:

a blocking section for dividing original data into blocks;

an orthogonal transform section for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting section for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding section for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform section for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form wherein in said inverse orthogonal transform section,

when the orthogonal transform coefficient obtained in said information embedding section is inverse orthogonal transformed, processing is further performed so that the value after inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

51. A recording medium which can be read by a computer and on which is recorded an information embedding program for realizing on a computer:

a blocking function for dividing original data into blocks;

an orthogonal transform function for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting function for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding function for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform function for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form,

wherein in said orthogonal transform section said orthogonal transform is a three dimensional orthogonal transform, and in said inverse orthogonal transform section, said inverse orthogonal transform is a three dimensional inverse orthogonal transform,

in said orthogonal transform function, the block from said blocking function is down-sampled so that the block size is smaller, after which the down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient,

in said inverse orthogonal transform function, after inverse orthogonally transforming the orthogonal transform coefficients obtained in said information embedding function, up sampling is performed so as to give a block of the size prior to down-sampling in said blocking function,

in said information embedding function, the entropy of the data value of the block to be processed is utilized for determining said predetermined value for quantization; and

in said inverse orthogonal transform function, when the orthogonal transform coefficient obtained in said information embedding function is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

52. A recording medium which can be read by a computer and on which is recorded an information embedding program for realizing on a computer:

a blocking function for dividing original data into blocks;

an orthogonal transform function for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting function for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding function for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform function for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form,

wherein in said orthogonal transform section said orthogonal transform is a three dimensional orthogonal transform, and in said inverse orthogonal transform section, said inverse orthogonal transform is a three dimensional inverse orthogonal transform,

in said orthogonal transform function, the block from said blocking function is down-sampled so that the block size is smaller, after which the down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient,

in said inverse orthogonal transform function, after inverse orthogonally transforming the orthogonal transform coefficients obtained in said information embedding function, up sampling is performed so as to give a block of the size prior to down-sampling in said blocking function,

in said information embedding function, a value of a low frequency domain in the orthogonal transform coefficient obtained in said orthogonal transform function is utilized for normalizing the orthogonal transform coefficients; and

in said inverse orthogonal transform function, when the orthogonal transform coefficient obtained in said information embedding function is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

53. A recording medium which can be read by a computer and on which is recorded an information embedding program for realizing on a computer:

a blocking function for dividing original data into blocks;

an orthogonal transform function for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting function for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding function for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform function for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form,

wherein in said orthogonal transform section said orthogonal transform is a three dimensional orthogonal transform, and in said inverse orthogonal transform section, said inverse orthogonal transform is a three dimensional inverse orthogonal transform,

in said information embedding function, the entropy of the data value of the block to be processed is utilized for determining said predetermined value for quantization; and

in said inverse orthogonal transform function, when the orthogonal transform coefficient obtained in said information embedding function is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

54. A recording medium which can be read by a computer and on which is recorded an information embedding program for realizing on a computer:

a blocking function for dividing original data into blocks;

an orthogonal transform function for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting function for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding function for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform function for carrying out inverse orthogonal transformation for embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form,

wherein in said orthogonal transform section said orthogonal transform is a three dimensional orthogonal transform, and in said inverse orthogonal transform section, said inverse orthogonal transform is a three dimensional inverse orthogonal transform,

in said information embedding function, a value of a low frequency domain in the orthogonal transform coefficient obtained in said orthogonal transform function is utilized for normalizing the orthogonal transform coefficients; and

in said inverse orthogonal transform function, when the orthogonal transform coefficient obtained in said information embedding function is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

55. A recording medium which can be read by a computer and on which is recorded an information embedding program for realizing on a computer:

a blocking function for dividing original data into blocks;

an orthogonal transform function for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting function for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding function for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform function for carrying out inverse orthogonal transformation for determining embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form wherein

in said information embedding function, the entropy of the data value of the block to be processed is utilized for determining said predetermined value for quantization; and

in said inverse orthogonal transform function, when the orthogonal transform coefficient obtained in said information embedding function is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

56. A recording medium according to claim 55, wherein in said orthogonal transform function said orthogonal transform is a two dimensional orthogonal transform, and in said inverse orthogonal transform function, said inverse orthogonal transform is a two dimensional inverse orthogonal transform.

57. A recording medium according to claim 56, wherein in said orthogonal transform function,

the block from said blocking function is down-sampled so that the block size is smaller, after which the down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient, and

in said inverse orthogonal transform function, after inverse orthogonally transforming the orthogonal transform coefficients obtained in said information embedding function, up sampling is performed so as to give a block of the size prior to down-sampling in said blocking function.

58. A recording medium according to claim 55, wherein in said orthogonal transform function,

the block from said blocking function is down-sampled so that the block size is smaller, after which the down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient, and

in said inverse orthogonal transform function, after inverse orthogonally transforming the orthogonal transform coefficients obtained in said information embedding function, up sampling is performed so as to give a block of the size prior to down-sampling in said blocking function.

59. A recording medium which can be read by a computer and on which is recorded an information embedding program for realizing on a computer:

a blocking function for dividing original data into blocks;

an orthogonal transform function for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting function for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding function for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform function for carrying out inverse orthogonal transformation for determining embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form wherein

in said information embedding function, a value of a low frequency domain in the orthogonal transform coefficient obtained in said orthogonal transform function is utilized for normalizing the orthogonal transform coefficients; and

in said inverse orthogonal transform function, when the orthogonal transform coefficient obtained in said information embedding function is inverse orthogonal transformed, processing is further performed so that the value after the inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.

60. A recording medium according to claim 59, wherein in said orthogonal transform function said orthogonal transform is a two dimensional orthogonal transform, and in said inverse orthogonal transform function, said inverse orthogonal transform is a two dimensional inverse orthogonal transform.

61. A recording medium according to claim 60, wherein in said orthogonal transform function,

the block from said blocking function is down-sampled so that the block size is smaller, after which the down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient, and

in said inverse orthogonal transform function, after inverse orthogonally transforming the orthogonal transform coefficients obtained in said information embedding function, up sampling is performed so as to give a block of the size prior to down-sampling in said blocking function.

62. A recording medium according to claim 59, wherein in said orthogonal transform function,

the block from said blocking function is down-sampled so that the block size is smaller, after which the down-sampled block is orthogonally transformed to obtain the orthogonal transform coefficient, and

in said inverse orthogonal transform function, after inverse orthogonally transforming the orthogonal transform coefficients obtained in said information embedding function, up sampling is performed so as to give a block of the size prior to down-sampling in said blocking function.

63. A recording medium according to claim 59, wherein said information embedding function comprises the steps of:

a calculating function for calculating a mean value of coefficients of the low frequency domain in the orthogonal transform coefficient obtained by said orthogonal transform step;

an obtaining function for obtaining a ratio between the mean value and a prescribed fixed value;

a normalizing function for normalizing all the orthogonal transform coefficient by multiplying by the ratio;

an embedding function for embedding the watermark-information into the normalized coefficients; and

an inverse-normalizing function for inverse-normalizing the information-embedded coefficients by dividing by the ratio.

75. A recording medium according to claim 71, wherein, when the watermark-information was embedded by the method of claim 63, said bit reading function comprises:

a calculating function for calculating mean value of coefficients of the low frequency domain in the orthogonal transform coefficient obtained by said object coefficient computing step;

an obtaining function for obtaining a ratio between the mean value and a prescribed fixed value;

a normalizing function for normalizing all the orthogonal transform coefficient by multiplying by the ratio; and

a reading function for reading each bit of the embedded watermark-information from the normalized coefficients.

64. A recording medium which can be read by a computer and on which is recorded an information embedding program for realizing on a computer:

a blocking function for dividing original data into blocks;

an orthogonal transform function for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting function for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding function for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform function for carrying out inverse orthogonal transformation for determining embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form wherein in said inverse orthogonal transform step,

when the orthogonal transform coefficient obtained in said information embedding function is inverse orthogonal transformed, processing is further performed by utilizing two pixel matrixes, one pixel matrix is obtained by;

changing a DC component value of the orthogonal transform coefficient obtained in said information embedding function to the minimum value of a defined range;

changing all values of the embedded coefficients to 0; and

inverse-orthogonal-transforming the changed matrix; and

the other pixel matrix is obtained by;

changing a DC component of the orthogonal transform coefficient obtained by said information embedding step to 0;

changing all values of the non-embedded coefficients to 0; and

inverse-orthogonal-transforming the changed matrix;

so that the value after inverse orthogonal transform does not exceed a defined range of pixel value of the original data form.

65. A recording medium according to claim 64, wherein in said inverse orthogonal transform function,

the processing so that the value after inverse orthogonal transform does not exceed a defined range, uses the data obtained by said inverse orthogonal transform, and the whole data is reduced with the mean value of the data as the center.

66. A recording medium which can be read by a computer and on which is recorded an information embedding program for realizing on a computer:

a blocking function for dividing original data into blocks;

an orthogonal transform function for obtaining coefficients by performing an orthogonal transformation for each block;

an embedding coefficient selecting function for determining coefficients in which watermark-information will be embedded by using a random sequence which is generated by initial value;

an information embedding function for sequentially embedding watermark-information, which has arbitrary length of bits, by quantizing value of said coefficients using a predetermined value for quantization; and

an inverse orthogonal transform function for carrying out inverse orthogonal transformation for determining embedded coefficients and non-embedded coefficients to form a block in which the watermark-information is embedded, as well as combining embedded blocks and to reconstruct data which is homogeneous to the original data form wherein in said inverse orthogonal transform function,

when the orthogonal transform coefficient obtained in said information embedding function is inverse orthogonal transformed, processing is further performed so that the value after inverse orthogonal transform does not exceed a defined range of pixel values of the original data form.