JP2003264683A - Digital watermark embedding apparatus and digital watermark detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital watermark embedding apparatus and a corresponding digital watermark detector which enable an embedding system to be selected according to the instruction of a user or an arbitrary status corresponding to a plurality of digital watermark systems. <P>SOLUTION: The digital watermark embedding apparatus is provided with an information embedding part 25 corresponding to a plurality of digital watermark embedding systems and a digital watermark embedding system switching part 24 for switching the digital watermark embedding system of the information embedding part 25 and embeds a digital watermark with a system selected out of the plurality of systems according to the arbitrary status. Besides, the digital watermark detector is provided with a plurality of digital watermark detecting systems, detects the digital watermark from a file with the digital watermark embedded therein, by the designated digital watermark system and can detect tampering. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital image processing technique, and more particularly to a digital watermark embedding device for embedding a digital watermark in image data, and a digital watermark detecting device for detecting a digital watermark from image data to detect tampering. Regarding

[0002]

2. Description of the Related Art In order to prevent illegal duplication of digital images, there has been considered a system in which image data is encrypted and only a reproducing system having a valid decryption key can reproduce the encrypted image information. However, once the code is decrypted, it is impossible to prevent further copying.

Therefore, a digital watermarking technology has been developed in which information such as an authentication code and a copyright is embedded in the image data itself while being processed to such a degree that it cannot be visually recognized. The digital watermark is integrated into the content itself,
Tampering with images, illegal copying, without increasing storage capacity
Unauthorized transfer can be prevented.

As a method of embedding information in image data, fast Fourier transform (FFT), discrete cosine transform (DC
Discrete Cosine Transform (T; Discrete Cosine Transform), wavelet transform is used to convert and decompose image data into frequency components, and information is embedded in high-frequency components that have little effect on image quality. Is used (pixel replacement type, bit replacement type), and color information of image data is used.

Here, an example of transmitting and receiving image data using a conventional digital watermark technique will be described. The electronic watermark embedding device receives an instruction from the image requesting terminal, images an object with an image capturing unit, and generates digital image data. The information embedding unit uses the particular digital watermark embedding method to specify specific information (authentication code, copyright information, etc.) in this image data.
Embed. Image data embedded with a digital watermark is
The transmission / reception unit of the digital watermark embedding device transmits the image data to the image requesting terminal that has requested the image data via the connection cable or the network.

The image requesting terminal receives the image data in which the digital watermark is embedded and stores it. Then, the electronic watermark detection device detects the electronic watermark of the image data to detect the presence or absence of falsification when necessary, and outputs the result (display, print, etc.). The image requesting terminal may also serve as the digital watermark detecting device.

[0007]

In a general digital watermark embedding method utilizing the frequency characteristic of image data, when the image data having a small number of high frequency components after the decomposition of frequency components is used, a large number of high frequency components are present. This is more difficult than when done on image data. In addition, information may not be completely embedded if there are few high-frequency components.
In such cases, the digital watermark embedding method must be changed.

However, the conventional digital watermark embedding device is compatible with only one type of digital watermark embedding system by one device. The same applies to the conventional digital watermark detection device. For this reason, it has not been possible to deal with such problems until now.

Therefore, the present invention is compatible with a plurality of digital watermark embedding methods, selects an embedding method according to a user's instruction, or conditions such as the amount of high frequency components of image data and the amount of information of compressed image data. It is an object of the present invention to provide a digital watermark embedding device capable of automatically selecting an embedding system according to the above, and a digital watermark detecting device compatible with a plurality of digital watermark embedding systems.

[0010]

The digital watermark embedding device of the present invention for achieving the above object is provided with a plurality of digital watermark embedding systems, and the digital watermark embedding system is selected from among them according to arbitrary conditions. A feature is that a digital watermark is embedded in the image data.

As the condition for selecting the digital watermark embedding method, for example, the amount of high frequency components of image data or compressed image data, or the amount of data amount of compressed image data can be adopted. When there are many high-frequency components such as image data, a digital watermark embedding method using frequency characteristics may be selected, and when there are few, other methods may be selected.

Such a digital watermark embedding device is provided with an information embedding unit corresponding to a plurality of digital watermark embedding systems and a digital watermark system switching unit for switching the digital watermark embedding system of the information embedding unit according to arbitrary conditions. realizable.

In addition, such a digital watermark embedding apparatus has an image data compression section for compressing image data, a frequency conversion section for frequency-converting the compressed image data, and a high-frequency component amount of the frequency-converted image data. A data amount detection unit for detecting, an information embedding unit corresponding to a plurality of digital watermark embedding systems, and a digital watermark system switching unit for switching the digital watermark embedding system of the information embedding unit according to the high frequency component amount of the compressed image data. It can also be realized by providing.

Further, such a digital watermark embedding device is compatible with a plurality of digital watermark embedding methods, an image data compression unit for compressing image data, a data amount detection unit for detecting the data amount of the compressed image data. It is also possible to realize by providing an information embedding unit for performing the operation and an electronic watermark method switching unit for switching the electronic watermark embedding method of the information embedding unit according to the data amount of the compressed image data.

With such a configuration, the digital watermark embedding method can be automatically selected according to an arbitrary condition of image data or according to a predetermined condition.

Here, the image data compression method is not particularly limited. For example, JPEG format and GIF format for still images, MPEG1, MPEG2 and MPEG4 formats for moving images, motion JPEG format, H.264. A compression method such as the H.261 format can be adopted.

Further, another digital watermark embedding device of the present invention for achieving the above object is characterized in that the digital watermark embedding method is selected according to the information of the terminal requesting the image, and the digital watermark is embedded in the image data. And

Here, as the information of the image requesting terminal or the user who has requested the image, for example, a network address of the terminal, a terminal identification number, a user ID, a password, encrypted data, etc. may be used alone or in combination. it can.

Such a digital watermark embedding device is provided with a transmission / reception unit connected to a network, an information embedding unit corresponding to a plurality of digital watermark embedding methods, and an electronic information embedding unit according to user information identified by the transmission / reception unit. This can be realized by including a digital watermark method switching unit that switches the watermark embedding method.

With such a configuration, different digital watermark embedding methods can be provided for each image requesting terminal, and it is possible to prevent leakage of information regarding the digital watermark embedding method among users who share the same digital watermark embedding device. Further, by using the identification information such as the user ID that does not depend on the image requesting terminal, the user can connect to the digital watermark embedding device without being restricted by the image requesting terminal.

Further, another digital watermark embedding apparatus of the present invention for achieving the above object is to embed a digital watermark in image data by selecting a digital watermark embedding method according to information or instructions of a user who requests an image. Is characterized by.

Such a digital watermark embedding device has a transmission / reception unit connected to a network, an information embedding unit corresponding to a plurality of digital watermark embedding systems, and a digital watermark embedding system of the information embedding unit according to a user's request. It can be realized by including a digital watermark method switching unit for switching.

With such a configuration, the user who requests the image can arbitrarily instruct the digital watermark embedding method. In addition, the optimum digital watermark embedding method can be selected according to the type and use of image data.

The identification information of the selected digital watermark embedding method may be embedded in the header portion of the image data. In this way, the receiving side can identify the digital watermark embedding method of the image data in which the digital watermark is embedded. This identification information may be encrypted.

Further, another digital watermark embedding apparatus of the present invention for achieving the above object may be provided with an image pickup unit for converting image information of an object into digital information in any one of the above configurations. Good. The image information may be a still image or a moving image.

Further, another digital watermark detecting apparatus of the present invention for achieving the above-mentioned object is provided with a plurality of digital watermark detecting methods, and the digital watermark detecting method is selected from among them, and the digital watermark detecting method is selected. The digital watermark is detected from the image data in which is embedded.

Such a digital watermark detecting apparatus includes a digital watermark detecting section corresponding to a plurality of digital watermark embedding methods, and a digital watermark method switching section for switching the digital watermark embedding method of the digital watermark detecting section according to a user's instruction. It can be realized by including and.

With this configuration, one digital watermark detecting device can support a plurality of digital watermark systems.

Further, another digital watermark detecting apparatus of the present invention for achieving the above object is the above-mentioned structure, and further selects a digital watermark detecting method by the identification information recorded in the header portion of the image data, It is characterized in that a digital watermark is detected from the image data in which the watermark is embedded.

Further, another digital watermark detecting apparatus of the present invention for attaining the above object is any one of the above configurations, and further selects a digital watermark detecting method according to information or instruction of a user who requests image data. The feature is that the digital watermark is detected from the image data in which the digital watermark is embedded.

Further, another digital watermark detecting apparatus of the present invention for achieving the above object is characterized by further detecting the presence or absence of tampering with the detected digital watermark in any of the above configurations.

Further, another digital watermark detecting apparatus of the present invention for achieving the above object is further connected to a digital watermark embedding apparatus via a network in any one of the above-mentioned configurations, and specifies a digital watermark embedding method. Any one or more of the identification information or the ID of the user who requests the image, the password, the information of the terminal, the network address of the terminal, and the encrypted data, and the image request of the user are transmitted to the digital watermark embedding device. At the same time, it is characterized in that it receives the digital watermark embedded image data transmitted from the digital watermark embedding device in response thereto.

The digital watermark embedding device having any one of the above configurations of the present invention or the digital watermark detecting device having any one of the above configurations of the present invention can be applied not only to a still image or a moving image but also to audio information or other digital data. It can also be applied to embedding a digital watermark in file information and detecting it.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to the drawings. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, and duplicate description will be omitted.

(First Embodiment) FIG. 1 is a diagram showing a configuration of a digital watermark embedding apparatus according to a first embodiment of the present invention and an image requesting terminal connected thereto via a cable. .

The image requesting terminal 10 comprises a control unit 11, a transmission / reception unit 12, a recording unit 13, an alteration detection unit 14, and a display unit 15. The control unit 11 inputs / outputs data and gives instructions. The transmission / reception unit 12 performs data transmission / reception and input / output. The recording unit 13 records digital watermark image data.
It has a recording medium for storing. The falsification detection unit 14 detects whether or not the digital watermark image data has been falsified, and outputs the result. The display unit 15 displays the digital watermark image and the alteration detection result.

On the other hand, the digital watermark embedding device 20 includes a transmission / reception unit 21, an image pickup unit 22, a digital watermark system switching unit 24,
The information embedding unit 25, the data amount detecting unit 26, and the frequency converting unit 27 are included.

The transmitting / receiving unit 21 transmits / receives data and inputs / outputs. The image capturing unit 22 captures an image at a timing when the image capturing instruction is received, and outputs captured image data obtained by converting the image capturing data into a digital signal. The digital watermark method switching unit 24
Switches the digital watermark method.

FIG. 2 is a diagram showing the configuration of the digital watermark system switching unit 24. The digital watermark system switching unit 24 is a storage unit 24.
-1, and includes a data amount comparison unit 24-2.

The storage section 24-1 stores and outputs the data extracted from the control data and the data indicating the corresponding digital watermark method. The data amount comparison unit 24-2 compares the input data with the reference value and instructs the digital watermark method.

The information embedding section 25 embeds information in the image data by the digital watermark technique by the designated digital watermark method. The information embedding unit 25 is composed of an image data output unit and a plurality of digital watermark modules. FIG. 3 is a diagram showing, as an example, the configuration of the information embedding unit 25 including the first digital watermark module 25-2, the second digital watermark module 25-3, and the third digital watermark module 25-4.

The image data output unit 25-1 is an image data output unit that outputs image data to a digital watermark module corresponding to the input switching control data. The first digital watermark module 25-2 is a digital watermark module that performs a process of embedding information by a digital watermark method suitable for image data with few high frequency components and outputs digital watermark image data in which information is embedded. The second digital watermark module 25-3 is a module that performs a process of embedding information by a digital watermark method suitable for image data having many high frequency components and outputs digital watermark image data in which information is embedded. The third digital watermark module 25-4 is a module that performs a process of embedding information by a digital watermark method suitable for image data having a medium high frequency component and outputs digital watermark image data in which information is embedded.

The data amount detector 26 detects the data amount of image data. The frequency conversion unit 27 converts the captured image data into frequency components.

In the image requesting terminal 10 of FIG. 1, G1
Is control data for controlling the digital watermark embedding device, and G2 is a recording data output signal for giving an instruction to output recorded image data. Further, G3 is digital watermark image data in which information is embedded by a digital watermark technique, G4 is recorded image data recorded on a recording medium, and G5 is a display unit for displaying the digital watermark image and the alteration detection result. It is the display data for displaying by.

The digital watermark embedding device 20 shown in FIG.
In the above, W1 is an image pickup timing signal for giving an image pickup instruction, W2 is picked up image data,
W5 is switching control data for instructing switching of the digital watermark method for embedding information, and W6 is digital watermark image data in which information is embedded by a digital watermark technique.
W7 is frequency component data output as a result of performing frequency conversion on the captured image data.
Reference numeral 8 is a high frequency component data amount indicating a high frequency component data amount. Further, W241 is determination reference data that is a reference value for comparing data amounts and determination reference data that specifies a digital watermark method corresponding to the determination reference data.
Is a data output signal for instructing the output of the judgment reference data W241.

In the connection cable for connecting the image requesting terminal 10 and the digital watermark embedding device 20 in FIG. 1, K1 is control data converted into a transmission format for the connection cable, and K2 is for the connection cable. The digital watermark image data has been converted into the transmission format.

When requesting image data from the image requesting terminal 10 to the digital watermark embedding device 20, the flow is as follows. The control data G1 is output from the control unit 11 of the image requesting terminal 10 and input to the transmission / reception unit 12. The control data G1 includes data instructing the output of the imaging timing signal W1 that gives an imaging instruction. Transmitter / receiver 12
Converts the input control data G1 into a data format for connection cable transmission, and converts the converted data (control data K
1) is transmitted to the transmission / reception unit 21 of the digital watermark embedding device 20 via the connection cable. Here, the connection cable may include a network.

The transmitting / receiving unit 21 of the digital watermark embedding device 20 that has received the control data K1 outputs the image pickup timing signal W1 in accordance with the instruction of the received data, and W1 is
It is input to the imaging unit 22. Digital watermark embedding device 20
When the image pickup timing signal W1 is input, the image pickup unit 22 starts the image pickup. The captured image is converted into a digital signal and input to the information embedding unit 25 and the frequency conversion unit 27 as captured image data W2.

The frequency converter 27 of the digital watermark embedding device 20 converts the picked-up image data W2 into frequency components, and then outputs them as frequency component data W7, which is input to the data amount detector 26. The above-mentioned DCT, FFT, or the like is used as the conversion method to the frequency component.

The data amount detection unit 26 of the digital watermark embedding device 20 detects the data amount of the high frequency component capable of embedding information in the input frequency component data W7, and switches the high frequency component data amount W8 to the digital watermark method. Input to the section 24.

Storage unit 24 of digital watermark method switching unit 24-
A reference value is set in 1, and the data amount comparison unit 24-
When receiving the data output signal W242 from No. 2, it is output to the data amount comparison unit 24-2 as the determination reference data W241. In the data amount comparison unit 24-2, the data amount detection unit 2
When the high-frequency component data amount W8 is input from 6, the data output signal W242 is output to the storage unit 24-1.
The criterion data W241 output from 4-1 is received.

Thereafter, the data amount comparison unit 24-2 compares the high frequency component data amount W8 with the judgment reference data W241. For example, when two reference values are set as the determination reference value (the smaller one is the first determination reference value and the larger one is the second determination reference value), the data amount comparison unit 24-
The image data amount W4 input in 2 is in three ranges of "first determination reference value or less", "greater than first determination reference value and less than second determination reference value", and "greater than second determination reference value". Determine where you belong. Based on the comparison result, the switching control data W5 instructing switching of the digital watermark method is output to the information embedding unit 25. When one value is set as the judgment reference value, it is judged whether the high frequency component data amount W8 belongs to a range below the judgment reference value or a range larger than the judgment reference value,
The switching control data W5 is output to the information embedding unit 25.

In the information embedding unit 25 of the digital watermark embedding device 20, the switching control data W5 and the captured image data W
When 2 is input, the captured image data W2 is output to the electronic watermark embedding module suitable for the captured image data W2 according to the switching control data W5. For example, the storage unit 24-
When two determination reference values are set to 1, the first electronic watermark module 25-2 embeds information in the captured image data having a high-frequency component data amount equal to or less than the first determination reference value. The second digital watermark module 25-3 embeds information in the captured image data having a data amount that is larger than the first determination reference value and equal to or smaller than the second reference value. The third digital watermark module 25-4 embeds information in the captured image data having a data amount larger than the second determination reference value. In each digital watermark module, just before embedding information, the data unique to the digital watermark method is described in the header part of the captured image data. After the information embedding process is completed, the digital watermark image data W6 is output to the transmitting / receiving unit 21.

Transmission / reception section 2 of digital watermark embedding device 20
1, the digital watermark image data W6 received from the digital watermark embedding unit 25 is converted into a data format for connection cable transmission, and the converted data (digital watermark image data K
2) is transmitted to the transmission / reception unit 12 of the control device 10 via the connection cable. Here, the connection cable may include a network.

The transmitting / receiving unit 12 of the image requesting terminal 10 which has received the digital watermark image data K2 converts it into a data format for recording and outputs the digital watermark image data G3 to the recording unit 13. Then, the recording unit 13 stores the digital watermark image data G3 received from the transmitting / receiving unit 12 in a recording medium such as a hard disk.

On the other hand, the control unit 11 of the image requesting terminal 10
The recording data output signal G2 for instructing the recording data output is
Output to the recording unit 13. The recording unit 13 is the control unit 1
When the recording data output signal G2 from 1 is received, the recording image data G4 is output to the falsification detection unit 14.

In the falsification detecting section 14 of the image requesting terminal 10,
The digital watermark method in which the information is embedded is read from the header portion of the input recorded image data G4. Alteration is detected by the designated digital watermark method, and the display data G5 of the alteration detection result is output to the display unit 15. Display 1
5 extracts and displays the recorded image data and the alteration detection result from the display data G5.

(Effects of First Embodiment) According to the configuration of the first embodiment, the following effects can be obtained.
One digital watermark embedding device can perform information embedding processing by different digital watermark systems. For image data that has not been compressed, it is possible to automatically select the digital watermark method based on the amount of high frequency component data when the image data is converted into frequency components. Therefore, in the information embedding process using the digital watermark, by performing the digital watermark method with a method suitable for each image data, it is possible to avoid the problem that the information cannot be completely embedded.

(Second Embodiment) FIG. 4 is a diagram showing a configuration of a digital watermark embedding device 20 of the second embodiment and an image requesting terminal 10 connected to the digital watermark embedding device 20 via a network. The configuration of the image requesting terminal 10 is the same as the configuration of the first embodiment, so description thereof will be omitted.

The digital watermark embedding device 20 comprises a transmission / reception unit 21, an image pickup unit 22, an image data compression unit 23, a digital watermark method switching unit 24, and an information embedding unit 25. The transmission / reception unit 21, the image pickup unit 22, the digital watermark method switching unit 24, and the information embedding unit 25 have the same configurations as those in the first embodiment, and therefore description thereof will be omitted.

FIG. 5 is a diagram showing the configuration of the image data compression unit 23 of the second embodiment, which is an example at the time of JPEG compression. The image data compression unit 23 compresses the captured image data and outputs the compressed image data. Further, when compressing the captured image data, the data amount of the high frequency component of the image data is detected and output. The image data compression unit 23
The CT calculation unit 23-1, the quantization unit 23-2, the entropy coding unit 23-3, and the data amount detection unit 23-4 are included. The DCT calculation unit 23-1 performs DCT calculation,
The quantizer 23-2 performs quantization, the entropy encoder 23-3 performs entropy encoding, and the data amount detector 23-4 detects the data amount of the high frequency component.

The data flow in the image requesting terminal 10 is the same as that in the first embodiment. Further, the data flow in the digital watermark embedding device 20 is W1, W2, W5, W
6, and W8 are the same as those in the first embodiment. W
Reference numeral 3 is compressed image data obtained by compressing captured image data, and W231 is D output as a result of the DCT operation.
CT data, and W232 is quantized data output as a result of the quantization processing. N1 in the network is control data converted into the network transmission format, and N2 is digital watermark image data converted into the network transmission format.

The transmitting / receiving unit 12 of the image requesting terminal 10 converts the input control data G1 into a data format for network transmission, and converts the converted data (control data N1) into
It is transmitted to the transmission / reception unit 21 of the digital watermark embedding device 20 via the network. Other operations in the image request terminal 10 are the same as those in the first embodiment.

The transmission / reception unit 21 of the digital watermark embedding device 20 which has received the control data N1 outputs the image pickup timing signal W1 in accordance with the instruction of the received data, and the image pickup unit 2
Enter in 2. The imaging unit 22 starts imaging when the imaging timing signal W1 is input. The captured image is converted into a digital signal and input to the image data compression unit 23 as captured image data W2.

The image data compression unit 23 of the digital watermark embedding device 20 uses JPEG for the captured image data W2.
It is converted to compressed image data by performing compression processing such as. In the present embodiment, an example of JPEG compression will be shown.

First, the picked-up image data W2 is input to the DCT calculator 23-1. DCT calculation is performed there, and D
The CT data W231 is output to the quantizer 23-2.
In the quantizer 23-2, the input DCT data W231
Is quantized and the quantized data W232 is output. The quantized data W232 output is the entropy coding unit 2
3-3 and the data amount detector 23-4. The entropy encoding unit 23-3 entropy-encodes the quantized data W232 and outputs the compressed image data W3 to the information embedding unit 25. On the other hand, in the data amount detector 23-4,
A high-frequency component data amount W8 is detected from the quantized data W232, and is output to the digital watermark method switching unit 24.

In the information embedding section 25 of the digital watermark embedding device 20, one of the input data is the picked-up image data W.
The operation is the same as that of the first embodiment, except that the data is changed from 2 to the compressed image data W3.

Transmission / reception section 2 of digital watermark embedding device 20
1 converts the digital watermark image data W6 received from the digital watermark embedding unit 25 into a data format for network transmission, and the converted data (digital watermark image data N
2) is transmitted to the transmission / reception unit 12 of the image requesting device 10 via the network.

The transmitter / receiver 12 receives the digital watermark image data N2 from the transmitter / receiver 21 of the digital watermark embedding device 20. Then, this is converted into a data format for recording of the image requesting terminal 10, and the digital watermark image data G is stored in the recording unit 13.
3 is output.

The operation of the recording unit 13 and the operation of tampering detection in the image requesting terminal 10 are the same as those in the first embodiment.

(Effects of Second Embodiment) According to the configuration of the second embodiment, the following effects can be obtained. One digital watermark embedding device can perform information embedding processing by different digital watermark systems. It is possible to automatically select a digital watermark method for image data that has been subjected to compression processing based on the amount of high frequency component data when the image data is converted into frequency components.
Therefore, in the information embedding process using the digital watermark, by performing the digital watermark method by a method suitable for each image, it is possible to avoid the problem that the information cannot be completely embedded.

(Third Embodiment) FIG. 6 is a diagram showing a configuration of a digital watermark embedding device 20 of a third embodiment and an image requesting terminal 10 connected to the digital watermark embedding device 20 via a network. The configuration of the image requesting terminal 10 is the same as the configuration of the first embodiment, so description thereof will be omitted.

The digital watermark embedding device 20 comprises a transmission / reception unit 21, an image pickup unit 22, an image data compression unit 23, a digital watermark method switching unit 24, an information embedding unit 25, and a data amount detection unit 26. Transmitter / receiver 21, imaging unit 22,
The digital watermark method switching unit 24 and the information embedding unit 25 have the same configurations as those of the first embodiment, and therefore their explanations are omitted.

FIG. 7 is a diagram showing the structure of the image data compression unit according to the third embodiment. The image data compression unit 23
The configuration is the same as that of the second embodiment except that the data amount detection unit 23-4 does not exist.

The data amount detection unit 26 of the digital watermark embedding device 20 detects the data amount of image data. The other configuration of the digital watermark embedding device 20 is the same as the configuration of the second embodiment.

The data flow is the same as that of the second embodiment except that W4 is the image data amount of the compressed image and W8 does not exist. Further, the configuration and operation of the image requesting terminal 10 are the same as in the first embodiment, and the network is the same as in the second embodiment.

Further, the control unit 11, the transmission / reception unit 12, the recording unit 13, the transmission / reception unit 21, the image pickup unit 22, and the information embedding unit 25.
The operation of the image data compression unit 23 is the same as that of the second embodiment. The operation of the image data compression unit 23 is the same as that of the DCT operation unit 23-1, the quantization unit 23-2, and the entropy encoding unit 23- of the second embodiment.
It is similar to the operation of 3.

In compression processing such as JPEG, data is compressed by performing processing such as reducing high frequency components of image data by quantization, giving a short bit string to a data value having a high appearance rate, and encoding. . Therefore, the amount of data is small for an image with few high-frequency components, such as when the data compression rate is high or when the color change of the imaging target is small. Therefore, the data amount detection unit 26 of the digital watermark embedding device 20 detects not the high frequency component but the data amount of the input compressed image data W3 and outputs the image data amount W4 to the digital watermark method switching unit 24.

In the digital watermark method switching unit 24 of the digital watermark embedding device 20, one of the input data is changed from the high frequency component data amount W8 to the image data amount W4.
The operation is similar to that of the second embodiment.

The operation of the recording unit 13 and the operation of tampering detection in the image requesting terminal 10 are the same as those in the first embodiment.

(Effects of the Third Embodiment) According to the configuration of the third embodiment, the following effects can be obtained. One digital watermark embedding device can perform information embedding processing by different digital watermark systems. In the process of embedding information by a digital watermark, the digital watermark method can be automatically selected based on the image data amount of the compressed image, so that it is possible to avoid the problem that the information cannot be completely embedded.

(Fourth Embodiment) FIG. 8 is a diagram showing a configuration of a digital watermark embedding device 20 of a fourth embodiment and an image requesting terminal 10 connected to the digital watermark embedding device 20 via a network. The configuration of the image requesting terminal 10 is the same as the configuration of the first embodiment, so description thereof will be omitted.

The digital watermark embedding device 20 comprises a transmission / reception unit 21, an image pickup unit 22, an image data compression unit 23, and an information embedding unit 25. Transmitter / receiver 21, imaging unit 2
2. The image data compression unit 23 has the same configuration as that of the third embodiment, and therefore its explanation is omitted.

FIG. 9 is a diagram showing the structure of the image data compression unit according to the fourth embodiment. Digital watermark embedding device 2
The information embedding unit 25 of 0 is an information embedding unit that embeds information in the compressed image data by the designated digital watermark method, and is composed of a plurality of digital watermark modules.
As an example, the first to third digital watermark modules 25-α,
It is assumed to consist of β and γ.

The image data output unit 25-1 outputs the compressed image data to the digital watermark module corresponding to the input switching control data. First digital watermark module 25
-Α is a digital watermark module that performs a process of embedding information in a digital watermark method that emphasizes the strength of the digital watermark and outputs digital watermark image data in which the information is embedded. The second digital watermark module 25-β is a digital watermark module that performs a process of embedding information by a digital watermark method with an emphasis on information embedding processing time, and outputs digital watermark image data in which information is embedded. The third digital watermark module 25-γ executes a process of embedding information by a digital watermark method in which the strength of the digital watermark and the information embedding processing time are medium, and outputs digital watermark image data in which the information is embedded. Is.

The other structure of the digital watermark embedding device 20 is the same as that of the third embodiment.

S1 in the digital watermark embedding device 20
Is the switching control data for instructing the switching of the digital watermark method for embedding information. If switching is not performed, the data will be empty. Other data and networks are the same as those in the third embodiment except that W4 and W5 do not exist.

Control data G1 is output from the control unit 11 of the image requesting terminal 10 and input to the transmission / reception unit 12. The control data G1 includes an imaging timing signal W1 that gives an imaging instruction.
Data for instructing the output of and the switching control data for specifying the digital watermark method.

Transmission / reception section 2 of digital watermark embedding device 20
1 receives the control data N1 and transmits the image pickup timing signal W1 to the image pickup unit 22 in accordance with the instruction of the received data. If the switching control data S1 exists, the switching control data S1 is output to the information embedding unit 25. The operations of the imaging unit 22, the image data compression unit 23, and the like are the same as those of the third embodiment except that the output destination of the compressed image data W3 is only the information embedding unit 25.

FIG. 9 is a diagram showing the structure of the information embedding unit 25. In the information embedding unit 25 of the digital watermark embedding device 20, when the switching control data S1 and the compressed image data W3 are input to the image data output unit 25-1, the compressed image data W3 is suitable according to the switching control data S1. The compressed image data W3 is output to the electronic watermark embedding module. When the switching control data S1 is empty data, the electronic watermark method designated last time is designated. First
The digital watermark module 25-α embeds information with an emphasis on the strength of the digital watermark. The second digital watermark module 25-β embeds information with an emphasis on information embedding processing time. The third digital watermark module 25-γ is
Information embedding is performed in both the strength of the digital watermark and the information embedding processing time. In each watermark module,
Just before embedding information, the data unique to the digital watermark method is described in the header of the compressed image data. After the information embedding process is completed, the digital watermark image data W6 is transferred to the transmitting / receiving unit 21.
Output to.

Transmission / reception section 2 of digital watermark embedding device 20
1, the operations of the transmission / reception unit 12, the control unit 11, and the recording unit 13 of the image requesting terminal 10 are the same as those in the third embodiment.

The operation of the recording unit 13 and the operation of tampering detection in the image requesting terminal 10 are the same as those in the first embodiment.

(Effects of Fourth Embodiment) According to the configuration of the fourth embodiment, the following effects can be obtained. One digital watermark embedding device can perform information embedding processing by different digital watermark systems. The digital watermark method can be switched arbitrarily on the image requesting terminal side. Therefore, it becomes possible to embed information in the image data by a digital watermark method suitable for the purpose of the image.

(Fifth Embodiment) FIG. 10 shows a digital watermark embedding device 20 according to the fifth embodiment and a plurality of image requesting terminals 10- connected to it through a network.
It is a figure which shows the structure of 1-10-x. Image request terminal 10
Since the configurations of -1 to 10-x are the same as the configurations of the first embodiment, description thereof will be omitted.

The digital watermark embedding device 20 comprises a transmission / reception unit 21, an image pickup unit 22, an image data compression unit 23, a digital watermark method switching unit 24, and an information embedding unit 25. Transmitter / receiver 21, imaging unit 22, image data compression unit 2
3. The digital watermark method switching unit 24 has the same configuration as that of the third embodiment, and therefore its explanation is omitted.

The information embedding section 25 of the digital watermark embedding device 20 embeds information in the compressed image data by the designated digital watermark method.

FIG. 11 is a diagram showing the configuration of the information embedding unit 25 of the digital watermark embedding device 20. The information embedding unit 25 includes an image data output unit 25-1 and a plurality of digital watermark modules. As an example, the first, second, and third digital watermark modules 25-A, 25-B, 2
5-C.

The image data output unit 25-1 outputs the compressed image data to the digital watermark module corresponding to the input switching control data. The first, second, and third digital watermark modules 25-A, 25-B, 25-C are different digital watermark modules. For example, it is a digital watermark method in which all three have the same digital watermark strength. Or
This is a digital watermark method with the same information embedding processing time.

In the data flow, S2 is the image request terminal 10
It is the IP address data indicating the IP address value of -x, and is otherwise the same as the third embodiment except that W4 does not exist. In addition, the image requesting terminal 10
The configuration and operation of are the same as those of the first embodiment, and the network is the same as that of the second embodiment.

The image requesting terminal 10-x outputs control data G1 from the control unit 11 and inputs it to the transmission / reception unit 12. The control data G1 includes data for instructing the output of the image pickup timing signal W1 for giving an image pickup instruction and IP address data indicating the IP address value of the image requesting terminal.

Transmission / reception section 2 of digital watermark embedding device 20
1 receives the control data N2 and transmits the image pickup timing signal W1 to the image pickup unit 22 in accordance with the instruction of the received data. Further, the IP address data S2 is output to the digital watermark system switching unit 24.

Imaging unit 2 of digital watermark embedding device 20
2. The operation of the image data compression unit 23 is the same as that of the second embodiment. Further, in the digital watermark method switching unit 24,
The operation is the same as that of the second embodiment, except that the input data is changed from the high frequency component data amount W8 to the IP address data S2.

In the information embedding unit 25 of the digital watermark embedding device 20, when the switching control data W5 and the compressed image data W3 are input to the image data output unit 25-1, the digital watermark embedding specified by the switching control data W5 is performed. The compressed image data W3 is output to the module. In each digital watermark module, the data unique to the digital watermark method is described in the header part of the compressed image data immediately before the information is embedded. After completion of the information embedding process, the digital watermark image data W
6 is output to the transmission / reception unit 21.

Transmission / reception section 2 of digital watermark embedding device 20
1, transmission / reception unit 12 of image request terminal 10-x, control unit 1
1, the operation of the recording unit 13 is similar to that of the third embodiment. Further, the operation of the recording unit 13 and the operation of tampering detection in the image requesting terminal 10 are the same as those in the third embodiment.

(Effects of the Fifth Embodiment) According to the configuration of the fifth embodiment, the following effects can be obtained. One digital watermark embedding device can perform information embedding processing by different digital watermark systems. The digital watermark system can be automatically switched according to the IP address value of the image requesting terminal. Therefore, it is possible to provide different digital watermarking methods for each terminal. By setting different digital watermarking methods depending on the image requesting terminal, it is possible to prevent leakage of information regarding the digital watermarking method to other users who share the same imaging device.

(Sixth Embodiment) FIG. 12 shows a digital watermark embedding device 20 of the sixth embodiment and a plurality of image requesting terminals 10-connected to it through a network.
It is a figure which shows the structure of 1-10-x. Image request terminal 10
The configurations of -1 to 10-x are the same as the configurations of the first and fifth embodiments, and therefore description thereof will be omitted.

Authentication unit 28 of digital watermark embedding device 20
Determines whether the user ID and password sent from the image requesting terminal match the registered one. The other configuration of the digital watermark embedding device 20 is the same as that of the fifth embodiment.

S3 in the digital watermark embedding device 20
Is control data obtained by converting the control data N1 from the network transmission format, and S4 is authentication data indicating the user ID and password designated by the image requesting terminal. Others are the same as those of the fifth embodiment except that S1 does not exist. The network is similar to that of the fifth embodiment.

The control section 11 of the plurality of image requesting terminals 10-1 to 10-x outputs the control data G1 and the transmitting / receiving section 12
To enter. The control data G1 indicates data for instructing the output of the imaging timing signal W1 that gives an imaging instruction, and the user ID from the image requesting terminals 10-1 to 10-x.
User ID data is included. The user ID does not depend on the image requesting terminals 10-1 to 10-x but depends on the user, and is used for connecting to the digital watermark embedding device 20 and for selecting the digital watermark method.

Transmission / reception section 2 of digital watermark embedding device 20
In No. 1, the control data S2 obtained by converting the control data N2 from the network transmission format to the transmission format in the imaging device is output to the authentication unit 28.

Authentication unit 28 of digital watermark embedding device 20
Then, the image pickup timing signal W1 and the user ID data S4 are extracted from the control data S3, and it is determined whether or not the user ID matches the registered data. If they match, the image pickup timing signal W1 is input to the image pickup unit 22, and the authentication data S4 is input to the digital watermark system switching unit 24. If they do not match, no image is taken.

Transmitting / receiving unit 2 of digital watermark embedding device 20
1, the operation of the imaging unit 22, the image data compression unit 23, the fifth
The digital watermark method switching unit 2 is the same as that of the first embodiment.
4. The function of the information embedding unit 25 is that the input data is IP
The other points are the same as those in the fifth embodiment except that the address data S2 is changed to the authentication data S4.

The operations of the transmission / reception unit 12, the control unit 11, and the recording unit 13 of the image requesting terminal 10-x are the same as those in the third embodiment. In addition, the recording unit 13 in the image requesting terminal 10
The operation and the operation of detecting falsification are the same as those in the third embodiment.

(Effect of Sixth Embodiment) According to the configuration of the sixth embodiment, the following effects can be obtained. One digital watermark embedding device can perform information embedding processing by different digital watermark systems. The digital watermark system can be automatically switched by the user ID and password. Since it does not depend on the image requesting terminal, it can be connected to the digital watermark embedding device anywhere. By setting different digital watermarking methods for each user, other users who share the same imaging device
It is possible to prevent leakage of information related to the digital watermark method.

Also in the first to fourth embodiments, it is possible to connect a plurality of image requesting terminals 10. Further, in the first embodiment, the connection between the image requesting terminal 10 and the digital watermark embedding device 20 can be changed to a network. In addition, in the second to sixth embodiments, the connection between the image requesting terminal 10 and the digital watermark embedding device 20 can be changed to a connection cable. Also, in the sixth embodiment, the user ID
Instead of, the encrypted data can be used and decrypted by the authentication unit.

(Seventh Embodiment) FIG. 13 is a diagram showing the structure of a digital watermark detection apparatus according to the seventh embodiment.
FIG. 14 is a diagram showing the configuration of the tampering detection unit of the digital watermark detection apparatus.

The digital watermark detection device 30 includes a recording unit 31,
Tampering detection unit 32, digital watermark method detection unit 33, display unit 3
It is configured to include 5. The recording unit 31 includes a recording medium for recording / saving the digital watermark image data. The falsification detection unit 32 detects whether or not the digital watermark image data has been falsified, and outputs the result to the display unit 35 as display data G5. The digital watermark method detection unit 33
The digital watermark embedding method is detected from the digital watermark image data G3, and the result is used as the digital watermark method data G6.
It is output to the digital watermark method switching unit 34. The digital watermark system switching unit 34 switches the digital watermark detection system of the tampering detection unit 32 according to the digital watermark embedding system detected by the digital watermark system detection unit 33. That is, one of the corresponding modules is selected from the plurality of digital watermark detection modules according to the digital watermark method data G6 input to the image data input unit 36 of the falsification detection unit 32. The display unit 15 displays the digital watermark image and the alteration detection result.

(Effect of Seventh Embodiment) According to the configuration of the seventh embodiment, one digital watermark detecting device can support a plurality of digital watermarking methods.

The preferred embodiments of the digital watermark embedding apparatus and the digital watermark detecting apparatus of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to these examples. It is obvious that a so-called person skilled in the art can come up with various changes or modifications within the scope of the technical idea described in the claims, and of course, the technical scope of the present invention is also applicable to them. Be understood to belong to.

[0120]

According to the present invention, a plurality of digital watermark embedding methods are supported, and an embedding method can be selected according to a user's instruction, or a high frequency component of image data or an information fee of compressed image data, etc. A digital watermark embedding device that can automatically select an embedding method according to conditions,
Also, a digital watermark detection device could be provided.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a digital watermark embedding device according to a first embodiment and an image requesting terminal connected to the digital watermark embedding device via a cable.

FIG. 2 is a diagram showing a configuration of a digital watermark method switching unit in FIG.

FIG. 3 is a diagram showing a configuration of an information embedding unit shown in FIG. 1, which includes first, second, and third digital watermark modules.

FIG. 4 is a diagram showing a configuration of a digital watermark embedding device according to a second embodiment and an image requesting terminal connected to the digital watermark embedding device via a network.

5 is a diagram showing a configuration of an image data compression unit in FIG.

FIG. 6 is a diagram showing a configuration of a digital watermark embedding device according to a third embodiment and an image requesting terminal connected to the digital watermark embedding device via a network.

7 is a diagram showing a configuration of an image data compression unit in FIG.

FIG. 8 is a diagram showing a configuration of a digital watermark embedding device according to a fourth embodiment and an image requesting terminal connected to the digital watermark embedding device via a network.

FIG. 9 is a diagram showing a configuration of an information embedding unit according to the fourth embodiment.

FIG. 10 is a diagram showing a configuration of a digital watermark embedding device according to a fifth exemplary embodiment and a plurality of image requesting terminals connected thereto via a network.

FIG. 11 is a diagram showing a configuration of an information embedding unit according to the fifth embodiment.

FIG. 12 is a diagram showing a configuration of a digital watermark embedding device according to a sixth embodiment and a plurality of image requesting terminals connected thereto via a network.

FIG. 13 is a diagram showing a configuration of a digital watermark detection device according to a seventh embodiment.

FIG. 14 is a diagram showing a configuration of a tampering detection unit of the digital watermark detection apparatus according to the seventh embodiment.

[Explanation of symbols]

10, 10-1 to 10-x Image requesting terminal 11 Control unit 12 Transmission / reception unit 13 Recording unit 14 Alteration detection unit 15 Display unit 20 Digital watermark embedding device 21 Transmission / reception unit 22 Imaging unit 23 Image data compression unit 23-1 DCT calculation unit 23-2 Quantization unit 23-3 Entropy coding unit 23-4 Data amount detection unit 24 Digital watermark method switching unit 24-1 Storage unit 24-2 Data comparison unit 25 Information embedding unit 25-1 Image data output unit 25-2 First digital watermark module 25-3 Second digital watermark module 25-4 Third digital watermark module 25-α First digital watermark module 25-β Second digital watermark module 25-γ Third digital watermark module 25-A First Digital Watermark Module 25-B Second Digital Watermark Module 25-C Third Digital Watermark Module 26 Data Detector 2 Frequency conversion unit 28 Authentication unit 30 Digital watermark detection device 31 Recording unit 32 Tamper detection unit 32-1 First digital watermark detection module 32-2 Second digital watermark detection module 32-3 Third digital watermark detection module 33 Digital watermark detection Unit 34 digital watermark method switching unit 35 display unit 36 image data input unit G1 control data G2 for controlling the digital watermark embedding device recording data output signal G3 digital watermark image data G4 recording image data G5 display data G6 digital watermark embedding system data W1 imaging Timing signal W2 Captured image data W231 DCT data W232 Quantized data W3 Compressed image data W4 Image data amount W5 of compressed image Switching control data W6 Digital watermark image data W7 Frequency component data W8 High frequency component data amount W241 Judgment reference data W24 Data output signal K1 Control data converted to transmission format for connecting cable K2 Digital watermark image data converted to transmission format for connecting cable N1 Control data converted to transmission format for network N2 Converted to transmission format for network Digital watermark image data S1 Switching control data S2 IP address value S3 of the image requesting terminal Control data N1 converted from the network transmission format S4 Authentication data indicating a user ID and password specified by the image requesting terminal

Claims (12)

[Claims] 1. A plurality of digital watermark embedding methods are provided,
A digital watermark embedding device characterized in that a digital watermark embedding method is selected from among them according to an arbitrary condition and a digital watermark is embedded in image data. 2. The digital watermark embedding apparatus according to claim 1, wherein a digital watermark embedding method is selected according to the amount of high frequency components of the image data to embed the digital watermark in the image data. 3. The digital watermark embedding apparatus according to claim 1, wherein a digital watermark embedding method is selected according to the amount of high-frequency components of the compressed image data, and the digital watermark is embedded in the image data. 4. The digital watermark embedding apparatus according to claim 1, wherein a digital watermark embedding method is selected according to the amount of compressed image data to embed the digital watermark in the image data. 5. The digital watermark embedding apparatus according to claim 1, wherein the digital watermark embedding method is selected according to the information of the terminal requesting the image, and the digital watermark is embedded in the image data. 6. The digital watermark embedding apparatus according to claim 1, wherein a digital watermark embedding method is selected according to information or instructions of a user who requests an image, and the digital watermark is embedded in the image data. 7. The digital watermark embedding apparatus according to claim 1, wherein identification information for identifying a selected digital watermark embedding method is recorded in a header portion of the image data. 8. An electronic device comprising a plurality of digital watermark detection methods, a digital watermark detection method is selected from among the digital watermark detection methods according to arbitrary conditions, and the digital watermark is detected from image data in which the digital watermark is embedded. Watermark detection device. 9. The digital watermark detection method is selected according to the identification information recorded in the header portion of the image data, and the digital watermark is detected from the image data in which the digital watermark is embedded. Digital watermark detection device. 10. The digital watermark detection method is selected according to the information or instruction of the user who requests the image data, and the digital watermark is detected from the image data in which the digital watermark is embedded. Digital watermark detection device. 11. The digital watermark detection apparatus according to claim 8, wherein presence or absence of falsification is detected in the detected digital watermark. 12. A user ID, password, terminal information, terminal network address, encrypted data, which is connected to a digital watermark embedding device via a network and requests identification information for identifying a digital watermark embedding method or an image. One or more of the above and a user's image request are transmitted to the electronic watermark embedding device, and in response thereto, the electronic watermark embedded image data transmitted from the electronic watermark embedding device is received. The electronic watermark detection device according to claim 8, wherein