JP2001223880A - Data processor, data processing method and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently deal with various watermarks embedded in digital data, to extract the watermarks and to detect whether the watermarks are destroyed by an attack. SOLUTION: In a data processor and a data processing method for embedding electronic watermark in digital data, watermark embedding means 101 to 104 for watermark information by various different systems are installed, and specified information for specifying the embedding means for watermark information being the object of embedding into digital data is embedded in digital data as common watermark information by a common watermark embedding means 105. When watermark information is read from digital data where the watermark is embedded, the common watermark extraction means extracts common watermark information having strong resistance, specifies the watermark embedding means used for actual watermark information from extracted common watermark information and extracts watermark information by using the watermark extraction method corresponding to the specified watermark embedding means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a data processing apparatus and method for embedding a digital watermark in digital data such as images and sounds, and a storage medium storing a program for executing the method.

[0002]

2. Description of the Related Art In recent years, computers and networks have been remarkably developed, and various kinds of information such as character data, image data, and voice data have been handled in computers and networks. Since such data is digital data, it is extremely easy to copy homogeneous data. Therefore, in order to protect the copyright of such data, a process of embedding copyright information, user information, and the like as image data in image data or audio data is often performed. Here, the digital watermark is
This is a technique in which predetermined processing is performed on image data and audio data to secretly embed other information into these data.

By extracting watermark information from data in which the digital watermark is embedded, copyright information, user information, identification information, and the like of the data can be obtained. It is possible to track unauthorized copying.

[0004] The first condition required for such a digital watermark is that the embedded information cannot be perceived, that is, the watermark can be embedded while suppressing the quality deterioration of the original digital information to a small extent (quality). The second condition is that the watermark information embedded in the digital information continues to remain, that is, the watermark information embedded in the digital information is not lost even by an attack such as an editing process such as a data compression process or a falsification process. That is (resistance). The third condition is that the amount of watermark information to be embedded can be selected according to the application (information amount). The conditions required for these digital watermarks generally have a trade-off relationship with each other. For example, when an attempt is made to realize a highly durable digital watermark, relatively large quality degradation often occurs, or the amount of watermark information that can be embedded is often reduced.

[0005] Taking a multi-valued still image as an example, methods for embedding a digital watermark can be broadly classified into two methods: a method for embedding in a spatial domain and a method for embedding in a frequency domain. Methods are known.

As an example of the former method of embedding a digital watermark in a spatial area, patchwork is used.
BM method (W. Bender, D. Gruhl, N. Morimoto, Techniqu
es for Data Hiding, "Proceedings of the SPIE", San
Jose CA, USA, February 1995) and GBRhoads, W. Linn: "
Steganographymethods employing embedded ", USP Pate
nt Number 5,636,292.

As an example of the latter method of embedding in the frequency domain, a method using discrete cosine transform
In addition to the TT method (Nakamura, Ogawa, Takashima, "Digital watermarking method in the frequency domain for copyright protection of digital images", SCIS '97 -26A, January 1997), using discrete Fourier transform A method of the Defense University (Onishi, Oka, Matsui, "Watermark Signature Method for Images Using PN Sequence", SCIS '9726B, January 1997)
And the method of Mitsubishi and Kyushu University using the discrete wavelet transform (Ishizuka, Sakai, Sakurai, "Experimental study on security and reliability of digital watermarking technology using wavelet transform", SCIS '97 -26D, 1997 1
Moon) and Matsushita's method (“Digital watermark image compression based on wavelet transform, robustness to conversion processing-”, Inoue, Miyazaki, Yamamoto, Katsura, S
CIS '98 -3.2. A, January 1998).

[0008] In the above method, the digital watermark embedding process and the extraction process correspond one-to-one, and are basically incompatible. Generally, the technique of embedding in the spatial domain is as follows.
It is said that the method using frequency conversion has little quality degradation but low durability, and it is said that the method using frequency conversion has relatively large quality degradation but strong resistance. The characteristics are different for each method, such as a method with little deterioration but a low resistance. Further, in order to protect the information in which the watermark is embedded, these digital watermarks include an algorithm for embedding the watermark, and information indicating the embedding position and the amount of change (hereinafter, referred to as “information”).
Key) is often kept secret. This is because the algorithm, the embedding position, and the like are analyzed to increase the resistance to a deliberate attack for removing a digital watermark.

[0009]

As described above, there are various digital watermarking systems. Also, when a certain system is improved, it is conceivable that the extraction algorithm differs between the original system and the improved system. In such a case,
Even if you try to extract the watermark information embedded in a certain image, if you do not know in advance which version of the digital watermark embedding method of which method,
There is a problem that the watermark cannot be extracted. In addition, when the embedded watermark cannot be extracted, it is impossible to determine whether the watermark embedded by another method is included or whether the embedded watermark is broken by an attack. Also occurs.

The present invention has been made in view of the above conventional example, and has as its object to provide a data processing method and apparatus capable of efficiently coping with various watermarks and extracting the watermarks. And

It is another object of the present invention to provide a data processing method and apparatus capable of detecting various watermarks and detecting whether the watermark has been destroyed by an attack or the like. It is in.

[0012]

In order to achieve the above object, a data processing apparatus according to the present invention has the following arrangement. That is, a data processing device that embeds a digital watermark in digital data, the watermark embedding unit embedding watermark information to be embedded in the digital data, and version information that specifies a version of an embedding method applied by the watermark embedding unit. And a common watermark embedding means for embedding in digital data.

In order to achieve the above object, a data processing apparatus according to the present invention has the following configuration. That is, claim 1
A data processing device for extracting the watermark information from digital data in which the watermark information is embedded by the data processing device according to the above, wherein a common watermark extraction unit that extracts the version information embedded by the common watermark embedding unit, Based on the version information extracted by the common watermark extracting unit, a specifying unit that specifies a version of an embedding method in which watermark information is embedded in the digital data, and a watermark information corresponding to the version specified by the specifying unit. Selecting means for selecting a watermark extracting means capable of performing extraction, and controlling means for controlling to extract the watermark information from the digital data using the watermark extracting means selected by the selecting means. In order to achieve the above object, The data processing device of the present invention has the following configuration. That is, a data processing method for embedding a digital watermark in digital data, wherein a watermark embedding step of embedding watermark information to be embedded in the digital data, and version information for specifying a version of an embedding method applied by the watermark embedding step are included in the data processing method. A common watermark embedding step of embedding in digital data.

To achieve the above object, the data processing method of the present invention comprises the following steps. That is, claim 5
A data processing method for extracting the watermark information from digital data in which the watermark information is embedded by the data processing method according to the above, wherein a common watermark extraction step of extracting the version information embedded in the common watermark embedding step, A specifying step of specifying a watermark embedding method in which watermark information is embedded in the digital data based on the version information extracted in the common watermark extracting step; and a watermark corresponding to the watermark embedding method specified in the specifying step. A selection step of selecting a watermark extraction method for extracting information, and a control step of controlling to extract the watermark information from the digital data using the watermark extraction method selected in the selection step. It is characterized by.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In this embodiment, the case where the digital data is image data will be described. However, such digital data is not limited to image data, and may be various digital data such as audio data and document data.

[Embodiment 1] FIG. 1 is a conceptual diagram illustrating a digital watermark embedding process according to a first embodiment of the present invention. In particular, a watermark is embedded by a digital watermark embedding method of different types or versions. FIG. 3 is a diagram illustrating an example including a watermark embedding unit and a common watermark embedding unit that embeds a common digital watermark.

In FIG. 1, reference numerals 101 to 104 denote digital watermark embedding means for embedding a watermark by different types or versions of digital watermark embedding methods, and 105 denotes a digital watermark embedding means using a common method. Reference numeral 110 denotes data to be distributed.

Here, common digital watermark embedding means 1
05 has the following features.

1) Common digital watermark embedding means 105
Realizes a robust digital watermark with a relatively small amount of information.

2) Common digital watermark embedding means 105
Embeds a digital watermark that can be extracted without a key or with a common key.

3) Common digital watermark embedding means 105
Embeds at least information identifying each digital watermarking scheme and / or its version.

4) Common digital watermark embedding means 105
Embeds a digital watermark having resistance to other digital watermark embedding (the embedding position can be changed, etc.).

Various schemes can be considered as a scheme for embedding a common digital watermark having the above characteristics. The following scheme is shown as an example for explaining the robustness. When the input data which is a copyrighted work is a still image, the image data of the still image is divided into 8 × 8 pixel blocks, and DCT (Discreate Cosine Transform) is performed for each block. Hereinafter, the block subjected to the DCT is referred to as D
One coefficient of CT coefficient block and DCT coefficient block is DC
T coefficient, set of DCT coefficient blocks of one image is DC
Let it be called a T coefficient block group.

FIG. 2A is a block diagram illustrating the configuration of such a common digital watermark embedding unit 105.

In FIG. 2A, the input image x is DCT-transformed by the image converter 301, and the output DCT coefficient block group is used as the input of the digital watermark embedding unit 302. Then, in these DCT coefficient block groups,
One DCT coefficient block in which a digital watermark is to be embedded is selected, and one DCT coefficient in the DCT coefficient block is quantized to embed one watermark bit. At this time, the size of the quantization step determines the embedding strength, and the size of the quantization step and the position of the selected DCT coefficient correspond to the key information.

As an example, the DCT at coordinates u, v
The value of the coefficient is represented by s {u, v}, the quantization step is represented by h, and digital watermark bits “0” or “1” are embedded according to the following rules.

A value a that satisfies a · h <s {u, v} ≦ (a + 1) · h (1) is obtained.

When embedded bit = 0, c０u, v｝ = b · h + h / 2 (2) (b is an even number of a or a + 1) When embedded bit = 1, c１u, v｝ = b · h + h / 2 (3) (b is the odd number of a or a + 1), and let c {u, v} be the DCT coefficient after embedding the digital watermark.

Finally, the block group is converted to an inverse transformer 303.
Is used to perform IDCT (Inverse DCT) to restore the 8 × 8 pixel block and reconstruct it.

As shown in FIG. 2B, the common digital watermark embedded in this way is subjected to the same DCT as when embedding the digital watermark by using the image converter 301.
The digital watermark extractor 705 selects DCT coefficients embedded using key information from the DCT coefficient block group output from the image converter 301, and b · h <c ｛u, v｝ ≦ (b + 1) · h .. (4) b is obtained. If the value of b is even, the embedded bit is determined to be "0", and if it is odd, it is determined to be "1".

In such a digital watermark embedding method, the following method is considered to enhance the durability.

When one DCT coefficient for embedding is selected from the DCT coefficient block, if a DCT coefficient representing a low frequency component is selected, the watermark resistance can be enhanced. This is because high frequency components are easily lost by image compression and various filtering processes,
This is because low frequency components are not easily lost.

In the above embedding method, one DCT coefficient block to be selected and one DCT coefficient to be embedded have been described. However, by increasing the number of DCT coefficient blocks, the tolerance can be increased. This means that for one bit, 1
If only one DCT coefficient is embedded, the value is likely to be lost due to image compression or various filtering processes. However, if the same bit is embedded in multiple DCT coefficients, all of those bits may be lost. This is because the nature is small.

The tolerance can also be enhanced by performing error correction coding on the embedded bits themselves. This is because even if some of the embedded bits are lost, they are restored by the error correction code. Here, it is clear that the higher the correction capability of the error correction code to be used, the stronger the tolerance. However, although these methods increase the robustness, there is a problem that the quality of the image is deteriorated because the low frequency component of the image is changed or many bits are embedded. Also, since the same bit is embedded using many DCT coefficients, the number of bits that can be embedded is often reduced.

If the reverse operation is performed, a digital watermarking technique can be realized in which the image quality is good but the amount of information that can be embedded is large, although the resistance is weak.

The technique for enhancing the above-described resistance is a DC method.
It can be said that the same tendency exists not only for the method using T but also for a method using, for example, a wavelet transform or a Fourier transform, or a method for directly operating a luminance value of a pixel.

Next, an embedding procedure according to this embodiment will be described with reference to FIG. Here, information specifying an embedding method (means) that is actually used for embedding a watermark by the common digital watermark embedding means 105 is, for example, “00 (= A)”, “01 (=
B), “10 (= C)”, and “11 (= D)”, and these are respectively inserted into the watermark embedding units 101 and 10.
2, 103, and 104 are 2-bit information that specifies the digital watermarking technique. However, it is clear that these may be set with other information.

First, using the common watermark embedding means 105, the above data 1) to 4) are applied to the data 110 to be distributed.
Digital watermark embedding means 1 to be used in the future, using a common robust digital watermark embedding method having the following characteristics:
The bit information corresponding to 01 to 104 is embedded. After that, information that is actually a digital watermark is embedded by using one of the digital watermark embedding means 101 to 104 specified by the bit information.

Here, the specified digital watermark embedding method and the common digital watermark embedding method do not interfere with each other, that is, the specified digital watermark embedding process affects common digital watermark information. If there is no technique (including changing the embedding position), the embedding order of the digital watermark may be reversed. Also,
The information to be embedded may be different for each watermark embedding method, or the same information may be used. Further, as the watermark information embedded for each method, various information such as copyright information, user information, and identification information can be considered.

FIG. 3 is a conceptual diagram showing a digital watermark extracting process according to the first embodiment.

In FIG. 3, reference numerals 201 to 204 denote digital watermark extracting means corresponding to the digital watermark embedding means 101 to 104 in FIG. 1, and the watermark information embedded by the corresponding watermark embedding means can be extracted. . Reference numeral 205 denotes a common watermark extracting unit that extracts a common watermark embedded in distribution data by the common digital watermark embedding unit 105.

In FIG. 3, when data 210 deemed to be an illegal copy is found or reported on the network, common watermark extracting means 205 is used to extract watermark information embedded with a common digital watermark. As a result, a digital watermark scheme in which a digital watermark is embedded, and / or
Alternatively, its version is specified, and one of the digital watermark extracting means 201 to 204 specified by the information is used to extract various embedded information.

According to the first embodiment, it can be seen that the digital watermark information can be efficiently extracted even in a system in which different digital watermarking systems are used together.
Further, the security when a watermark cannot be found can be improved for the following reasons.

If the watermark information that should have been embedded in the data cannot be found, whether the watermark information originally did not exist in the data, whether the watermark was embedded by another watermark embedding method, or It is difficult to distinguish whether the embedded watermark information has been destroyed by an attack.

However, since the common digital watermark in the first embodiment has a high resistance, it is difficult to destroy the common digital watermark information by attack. Therefore, when watermark information based on a common digital watermark is extracted,
Originally, the possibility that digital watermark information was not included is excluded.

Next, the method of embedding a digital watermark in each method is arbitrary, but when embedding detailed information, the amount of information to be embedded increases. Therefore, in order to suppress the deterioration of image quality due to such a large amount of embedded information, an electronic watermark is often embedded by an electronic watermarking method having relatively low tolerance. Therefore, after the common digital watermark information is extracted by the common digital watermark extraction method, if the watermark information that should have been embedded by each watermark embedding unit cannot be extracted, the embedded digital watermark information is used in the attack. It is considered that they have been destroyed due to such factors.

FIG. 4 is a flowchart showing a digital watermark embedding process according to the first embodiment.

First, in step S1, a digital watermark is embedded in the distribution data 110 by using the common watermark embedding means 105, and the version of the embedding method applied by the next digital watermark embedding means is applied by the common digital watermark. To identify. Then, the process proceeds to step S2, in which the distribution data 110 is embedded with the digital watermark embedding unit of the version specified in step S1.
Embed a digital watermark. Thus, distribution data in which the digital watermark is embedded can be created.

FIG. 5 is a flowchart showing a process for extracting a digital watermark from data in which a digital watermark is embedded in this way.

First, in step S11, a common digital watermark embedded in the distributed data 210 is extracted.
Then, in step S12, it is checked whether or not this common digital watermark has been detected.
Then, it is determined that the digital watermark was not originally embedded in the data 210, and the process is terminated.

If it is determined in step S12 that the common digital watermark has been embedded, the process proceeds to step S14, where the digital watermark embedded by the watermark embedding method of the version specified by the common digital watermark is replaced by the method. Is extracted using the watermark extracting means corresponding to. Then, in step S15, it is checked whether the embedded digital watermark has been normally extracted, and if so, the extracted digital watermark is adopted and the process ends. If not, the flow advances to step S16 to determine that the embedded digital watermark has been destroyed for some reason.

As described above, according to the first embodiment, there is a watermark method in which common watermark information is embedded using a common digital watermark embedding method having high durability, and the watermark information is actually embedded with the common watermark information. By specifying the version of the applied embedding method, it is possible to increase the possibility that the embedded digital watermark can be detected as compared with the case where the digital watermark is embedded using only various digital watermark embedding methods. Also, it can be determined more reliably whether the digital watermark has been destroyed by an attack.

In the first embodiment, four types of digital watermark embedding methods have been described as examples. However, it is apparent that any number of methods can be similarly implemented.

[Embodiment 2] FIG. 6 is a conceptual diagram illustrating a digital watermark embedding process according to Embodiment 2 of the present invention.

In the figure, reference numerals 401 to 404 denote different types or versions of digital watermark embedding methods.
A digital watermark embedding unit for embedding a watermark in distribution data 410 is shown. Here, digital watermark embedding means 401 to
The information embedded using each of the digital watermarking schemes 404 is characterized in that it is not extracted by other digital watermarking schemes or very difficult to extract. In general, this feature is satisfied if the digital watermarking method is different, but if the types of the digital watermarking methods of the digital watermark embedding means 401 to 404 are relatively small, it can be confirmed in advance by experiments or the like. A combination of digital watermarking schemes can be selected.

The procedure for embedding these digital watermarks is as follows.

An electronic watermark is embedded in the distribution data 410 by any one of the electronic watermark embedding means 401 to 404. Here, the digital watermark embedding unit to be employed is determined by the time when the digital watermark embedding units 401 to 404 are used, or in the case of a different digital watermarking method, when the digital watermark is embedded. In addition, the information to be embedded as the digital watermark is operated to embed the digital watermark including the information (specific information) determined by the digital watermark embedding units 401 to 404. For example, as shown in FIG. 8, specific information (several bits) (“111
1 "), and individual watermark information to be actually embedded is embedded in the remaining area 602.

FIG. 7 is a conceptual diagram illustrating a digital watermark extracting process according to the second embodiment of the present invention.

In the figure, reference numerals 501 to 504 denote digital watermark extracting means capable of extracting the watermark embedded by the digital watermark embedding means 401 to 404 in FIG. 5
Reference numeral 10 denotes data in which a digital watermark is embedded according to the configuration shown in FIG.

The procedure for extracting a digital watermark in FIG. 7 will be described below.

When data 510 considered to be an illegal copy is found, reported or distributed, first, a digital watermark embedded in the data 510 is extracted by the digital watermark extracting means 501. If the digital watermark cannot be extracted by this, other digital watermark extracting means 502 to 50
4 is sequentially used to extract a digital watermark. When a digital watermark is extracted by any of these extraction means, information obtained by the extraction is used as watermark information.

On the other hand, when the watermark information is not obtained by all the digital watermark extracting means, it is determined that the digital watermark information was not originally embedded in the data 510. At this time, whether or not the information is watermark information is determined based on the specific information.

For example, as shown in FIG. 8, when it is determined that the first few bits (specific information) of the digital watermark are all 1, the first few bits 601 of the information extracted by the digital watermark extracting means are determined. Are all “1” and the information extracted from the remaining area 602 is meaningful information, it is determined that the extracted information is the watermark information. This is because, as described above, since the watermark embedding methods of the digital watermark embedding means 401 to 404 are mutually exclusive, the digital watermark embedded by a certain watermark embedding method happens to be identified by another method. This is because the probability of being extracted as meaningful information including information is considered to be extremely low.

If the first few bits 601 of the information extracted by the digital watermark extracting means are all “1” and the information extracted from the remaining area 602 is not meaningful information, the watermark information May be determined to have been destroyed by an attack or the like.

FIG. 9 is a flowchart showing a digital watermark embedding process according to the second embodiment.

First, in step S21, the distribution data 410
Of the digital watermark embedding means 401 to 404 for embedding a digital watermark in the electronic document. At the time of this selection, the digital watermarking means to be selected is determined by the time when the digital watermark embedding means 401 to 404 is used or, if the digital watermarking method is a different version, the time when the digital watermark is embedded. And step S
In step 22, the digital watermark is embedded in the data 410 by using the selected digital watermark embedding means. Here, the information to be embedded as a digital watermark includes information defined by the digital watermark embedding units 401 to 404 (specific information 601 in FIG. 8).

FIG. 10 is a flowchart showing a digital watermark extracting process according to the second embodiment.

In step S31, when the data 510 embedded with the digital watermark is input, the process proceeds to step S32, where the digital watermark extracting means 501 for extracting the digital watermark is selected, and the selected digital watermark extracting means is selected. Using 501, a digital watermark embedded in the data 510 is extracted (step S33). Next, the process proceeds to step S34, where it is determined whether or not the digital watermark has been extracted. If the digital watermark has not been extracted, the process proceeds to step S36, and one of the other digital watermark extracting means 502 to 504 is selected, and the process returns to step S33. The digital watermark is extracted using the selected digital watermark extracting means. Using any of these digital watermark extracting means, the data 510
If a digital watermark has been extracted from, the process proceeds to step S35, and information obtained thereby is used as watermark information.

On the other hand, all digital watermark extracting means 501 to 501
If the watermark information has not been obtained by using 504, the process proceeds from step S37 to step S38, and it is determined that the digital watermark information was not originally embedded in the data 510. At this time, whether or not the information is watermark information is determined based on the specific information.

In this case, even if the specific information is included in the area 601 and the information in the area 602 has no meaning, it may be determined that the digital watermark has been destroyed.

In the first embodiment, a plurality of digital watermark embedding methods can be easily mixed without depending on individual digital watermarking methods and the number of types thereof. The problem is that the embedding method of the common watermark cannot be improved, and two embedding methods such as embedding of a common electronic watermark and embedding of an individual electronic watermark in the embedding process of the electronic watermark must always be performed.

On the other hand, according to the second embodiment, since a common digital watermarking method is not used, embedding of a digital watermark can be realized using one digital watermark embedding means.
There is an advantage that it is not necessary to use a common digital watermark embedding method. However, this is troublesome when there are many types of digital watermark embedding methods, but is particularly effective when the number of types is relatively small or when it is desired to extract only digital watermarks embedded by a specific embedding method. is there.

The present invention is not limited to an apparatus and a method for realizing the above-described embodiment and a method for performing a combination of the methods described in the embodiment, but a computer (CPU or CPU) in the above-described system or apparatus. MP
U), a program code of software for realizing the above-described embodiment is supplied, and the computer of the system or the apparatus operates the various devices according to the program code to realize the above-described embodiment. It is included in the category of the present invention.

In this case, the software program code itself implements the functions of the above-described embodiment, and the program code itself and means for supplying the program code to the computer, specifically, A storage medium storing the above program code is included in the scope of the present invention.

As a storage medium for storing such a program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, magnetic tape, nonvolatile memory card, ROM, etc. can be used.

In addition to the case where the computer controls various devices in accordance with only the supplied program code to realize the functions of the above-described embodiment, the above-mentioned program code is not limited to the operating system running on the computer. Such a program code is included in the scope of the present invention even when the above-described embodiment is realized in cooperation with an (operating system) or other application software.

Further, after the supplied program code is stored in a memory provided in a function expansion board of a computer or a function expansion unit connected to the computer, the function expansion board or function is stored based on the instruction of the program code. The case where the CPU or the like provided in the storage unit performs part or all of the actual processing, and the above-described embodiment is realized by the processing is also included in the scope of the present invention.

As described above, according to the present embodiment, even when digital watermarking schemes having different schemes and versions are mixed, it is possible to specify an embedded digital watermark and extract the watermark information. This makes it possible to effectively and efficiently cope with a case where a plurality of digital watermarking schemes exist due to improvement of the digital watermarking scheme.

Further, the security when a watermark cannot be found can be improved as compared with the case where each digital watermarking method is used alone.

[0080]

As described above, according to the present invention, it is possible to efficiently deal with various watermarks and extract the watermarks.

Further, according to the present invention, for various watermarks, the watermark can be detected, and it is also possible to detect whether the watermark has been destroyed by an attack or the like.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram illustrating a digital watermark embedding process according to Embodiment 1 of the present invention.

FIG. 2 is a conceptual diagram illustrating embedding and extraction of a common digital watermark according to the first embodiment.

FIG. 3 is a conceptual diagram illustrating a digital watermark extraction process according to the first embodiment of the present invention.

FIG. 4 is a flowchart illustrating a digital watermark embedding process according to the first embodiment of the present invention.

FIG. 5 is a flowchart illustrating a digital watermark extraction process according to the first embodiment of the present invention.

FIG. 6 is a conceptual diagram illustrating a digital watermark embedding process according to Embodiment 2 of the present invention.

FIG. 7 is a conceptual diagram illustrating a digital watermark extraction process according to Embodiment 2 of the present invention.

FIG. 8 is a diagram illustrating digital watermark information according to the second embodiment.

FIG. 9 is a flowchart illustrating a digital watermark embedding process according to the second embodiment of the present invention.

FIG. 10 is a flowchart illustrating a digital watermark extraction process according to Embodiment 2 of the present invention.

Claims (9)

[Claims] 1. A data processing apparatus for embedding an electronic watermark in digital data, comprising: a watermark embedding unit for embedding watermark information to be embedded in the digital data; and a version for specifying a version of an embedding method applied by the watermark embedding unit. And a common watermark embedding unit for embedding information in the digital data. 2. The data processing apparatus according to claim 1, wherein the common watermark embedding unit embeds the version information with high robustness. 3. The means for embedding the common watermark, means for performing discrete frequency conversion on the digital data, means for embedding the version information by quantizing the transform coefficient converted by the means for converting, and the information 2. The data processing apparatus according to claim 1, further comprising: an inverse conversion unit that performs an inverse conversion of the conversion unit on the data in which is embedded. 4. A data processing apparatus for extracting the watermark information from digital data in which the watermark information is embedded by the data processing apparatus according to claim 1, wherein the version information embedded by the common watermark embedding unit is extracted. A common watermark extracting unit to be extracted; a specifying unit that specifies a version of an embedding method in which watermark information is embedded in the digital data based on the version information extracted by the common watermark extracting unit; Selecting means for selecting watermark extracting means capable of extracting watermark information corresponding to the version, and extracting the watermark information from the digital data using the watermark extracting means selected by the selecting means. And control means for controlling Over data processing apparatus. 5. A data processing method for embedding a digital watermark in digital data, comprising: a watermark embedding step of embedding watermark information to be embedded in the digital data; and a version for specifying a version of an embedding method applied in the watermark embedding step. A common watermark embedding step of embedding information in the digital data. 6. The data processing method according to claim 5, wherein in the common watermark embedding step, the version information is embedded with high robustness. 7. The common watermark embedding step includes a conversion step of performing a discrete frequency conversion on the digital data; a step of quantizing the conversion coefficient converted in the conversion step to embed the version information; The data processing method according to claim 5, further comprising an inverse conversion step of performing an inverse conversion of the conversion step on the data in which the information is embedded. 8. A data processing method for extracting the watermark information from digital data in which watermark information is embedded by the data processing method according to claim 5, wherein the version information embedded in the common watermark embedding step is A common watermark extracting step to be extracted; a specifying step of specifying a watermark embedding method in which watermark information is embedded in the digital data based on the version information extracted in the common watermark extracting step; A selection step of selecting a watermark extraction technique for extracting watermark information corresponding to the watermark embedding technique; and controlling to extract the watermark information from the digital data using the watermark extraction technique selected in the selection step. A data processing method comprising: 9. A computer-readable storage medium storing a program for executing the data processing method according to claim 5. Description: