JP2002101397A - Device and method for embedding additional information, and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To embed additional information into a main information signal so that the additional information can be detected even in any encoding method/ format. SOLUTION: The additional information is separately encoded by two or more different coding method/format, and embedding patterns encoded by the respective methods are multiplexed and superimposed on the main information signal. At the time of detecting the additional information, the additional information can be detected by decoding the additional information according to at least any encoding method/format. The increase in information quantity is minimized and the additional information can efficiently be transmitted compared with a case when a plurality of embedding patterns are simultaneously multiplexed and superimposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an additional information embedding apparatus and method for embedding additional information in a main information signal such as a video signal, a music signal, and a text signal, and more particularly to a different encoding method and a different encoding key. The present invention relates to an additional information embedding device and method for embedding additional information so that additional information can be detected in any of embedded patterns coded in a plurality of types of encoding formats.

[0002]

2. Description of the Related Art Recently, digital recording devices such as digital VTRs and MD (Mini Disc (trademark)) recording and reproducing devices have begun to spread. DVD with recording function
(Digital Video Disc (trademark) or Digital
Versatile disk) devices have also appeared,
It is being mounted on devices such as computers (PCs).

According to such a digital information recording apparatus, it is extremely easy to copy or falsify digital data or contents, and it can be said that the apparatus is even exposed to the danger of copyright infringement. Therefore, strengthening the copyright law and other laws and regulations is not enough. From the viewpoint of information technology, we support the legitimate use of data and content or eliminate illegal use to expand copyright protection. I think I need to do that.

In a digital information recording apparatus, a digital video signal or a digital audio signal as a main information signal, or digital data for a computer may be attached. In this case, the additional information signal is a digital signal. For example, a header portion added to data in block units of a digital information signal, other TOC
It can be added to the digital information signal as being recorded in an area clearly distinguished from the digital information signal body, such as an area of (Table Of Contents).

As additional information, for example, information for controlling copying of data and contents (COPYONECE and NEVER COPY)
) And copyright information (such as a copyright notice)
Copy control can be performed.

In a conventional data transmission / distribution / distribution system, the additional information is not superimposed directly on the digital information signal, but is added to an indirect portion such as a header. For this reason, the additional information can be deleted relatively easily by filtering or tampering, so that it becomes impossible for the recording device or the reproducing device to detect the necessary additional information. In particular, when additional information includes control information or copyright information to prevent unauthorized duplication of data or content, the initial purpose cannot be achieved due to the lack of additional information. Invite.

In addition, when the additional information is added to the indirect portion of the information signal as described above, only the main information signal is obtained when the digital information is converted into an analog signal, and thus the additional information is lost. Will be lost. This means that even if a control signal for preventing duplication as described above is superimposed as an additional information signal and measures are taken to suppress illegal digital information signal duplication, it is converted to an analog signal. It means that such measures no longer have any effect in the subsequent process.

[0008] In view of such problems in protecting digital data and contents, "digital watermarking" (Digital Watermark) is a technique for adding an additional information signal to a digital information signal itself.
Watermarking or Data Hiding) has been spotlighted and various proposals have been made.

The digital watermark means that additional information is embedded in a content such as an image or music in a form almost invisible or inaudible (for example, “Data Hiding Technology Supporting Digital Watermark”). (Upper / lower) "
(Nikkei Electronics February 24, 1997 and March 10, 1997). In addition, this article is "Tec
hniques for data hiding ", IBM System Journal, vol.
35, NOS 3 & 4, 1996 Article based on p313-339. ).

The digital watermark is realized by inserting information different from the original information into a part of the host signal by utilizing the statistical property of the host signal as the embedding destination. For example, by embedding the copyright information with a digital watermark, when the content is later collected, the watermark, that is, the copyright information is raised, and the data distribution route and the use right are checked, and the copy control information is verified. Thus, illegal copying can be suppressed.

[0011] However, when each supplier of digital data or content encodes the additional information by an individual encoding method (or by using a different key) and embeds the additional information in the main information signal, the information recording / reproducing is performed. If the decoder on the side of the playback device (for example, a DVD recorder) does not support the same encoding system as the content supplier, the additional information embedded in the main information signal cannot be detected.・ The certainty of control will be lost.

[0012] Even if the original additional information is the same, if the encoding system is different, the signal after encoding the additional information, that is, the embedding pattern inserted into the main information signal will be different. Even if the encoding method is the same, if the key information used for encoding is different, the embedded pattern after encoding is different even if the same additional information is the same.

[0013] In the industry, a plurality of encoding formats coexist at present. Therefore,
If the digital information recording / reproducing apparatus adopts a mechanism that can detect only the additional information embedded in a specific encoding format, the additional information according to other encoding formats cannot be detected. As a result, unified copy control cannot be performed, and the reliability of data and content protection is lost.

In order to eliminate such a problem, it is necessary to recognize the existence (coexistence) of various encoding systems and encoding formats, and to adopt any encoding system / encoding format. It is preferable that the additional information can be reliably detected from the main information signal.

Incidentally, Japanese Patent Application Laid-Open No. 2000-92461 (corresponding to US application Ser. No. 09/3) already assigned to the present applicant.
92050) has an additional configuration configured to be able to extract, from the converted video signal, additional information that is spectrum-spread and superimposed on the converted video signal even when the video signal is converted into a video signal having a different aspect ratio. An information superposition method is disclosed.

However, the additional information superimposing method described in the publication solves the problem that additional information cannot be detected due to a difference in aspect ratio, that is, an image format. It does not solve the problem that information cannot be detected.

[0017]

SUMMARY OF THE INVENTION An object of the present invention is to provide an excellent information embedding apparatus capable of suitably embedding additional information in a main information signal such as an image or music in a form almost invisible or inaudible. An object of the present invention is to provide an additional information embedding device and method.

It is a further object of the present invention to provide additional information such that an embedded pattern encoded by a plurality of types of encoding formats having different encoding systems and encoding keys can be detected in any encoding system / format. It is an object of the present invention to provide an excellent apparatus and method for embedding additional information, which can embed in a main information signal.

[0019]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and a first aspect of the present invention is an additional information embedding apparatus or method for superimposing additional information on a main information signal. Generating means or a step of generating a first embedded signal from the additional information and generating a second embedded signal from the additional information, and superimposing each embedded signal generated by the generating means on the main information signal. An additional information embedding device or method.

Here, the superimposing means or the step includes a step of dividing a region into a plurality of regions and multiplexing the divided regions, a frequency band or a DC.
T (Discrete Cosine Transform)
Each embedment signal may be superimposed on the main information signal by any one of multiplexing methods of frequency multiplexing multiplexed by a coefficient or the like and overwriting multiplexing overwriting a plurality of embedding patterns.

[0021] The superimposing means or step may include the first step.
A first section in which an embedding signal is superimposed on a main information signal and a second section in which the second embedding signal is superimposed on a main information signal appear repeatedly in the time direction of the main information signal. The first embedding signal and the second embedding signal may be superimposed on the main information signal.

The superimposing means or step may embed different embedding signals in the main information signal at predetermined time intervals.

For example, each embedding signal may be time-division multiplexed at approximately 10 second intervals and superimposed on the main information signal.

[0024] The superimposing means or step may embed different embedding signals in the main information signal for each of a predetermined number of frames or a predetermined number of fields.

Further, the superimposing means or the step comprises the first step.
The embedding signal and the second embedding signal may be respectively superimposed on a plurality of regions obtained by dividing a signal unit constituting the main information signal.

Here, when the main information signal is a video signal, the signal unit of the main information signal corresponds to a frame or a field constituting the video signal.

For example, the superimposing means or step may time-division multiplex each embedded signal at an interval of a multiple of two frames or a multiple of five fields and superimpose it on the main information signal.

[0028] The generating means or step may generate the first embedded signal and the second embedded signal from the same additional information.

Further, the generating means or step generates the first embedded signal and the second embedded signal using key information, and generates a different embedded signal from the additional information due to a difference in key information to be used. You may.

Further, the generating means or step may generate different embedded signals from the same additional information depending on a difference in encoding method.

According to a second aspect of the present invention, there is provided a recording medium on which a signal in which additional information is superimposed on a main information signal is recorded, wherein a first embedded signal generated from the additional information, A recording medium characterized by recording a signal multiplexed with the generated second embedded signal and superimposed on the main information signal.

According to a third aspect of the present invention, there is provided a recording medium recording a signal in which additional information is superimposed on a main information signal, wherein a first embedded signal is generated from the additional information.
A generating step of generating a second embedding signal from the additional information, a superimposing step of superimposing each embedding signal generated in the generating step on a main information signal, and superimposing each embedding signal generated in the superimposing step. A recording step of recording signals on the recording medium.

[0033]

In the additional information embedding apparatus and method according to the present invention, the additional information is separately encoded by two or more different encoding systems / encoding formats, and the embedding pattern encoded by each system is spatially multiplexed. Multiplexing by frequency multiplexing, overwriting multiplexing, or
After time division multiplexing, it is superimposed on the main information signal.

Therefore, when detecting an embedding pattern, that is, additional information, the additional information is detected by performing decoding in accordance with at least one of the encoding method / encoding format used when the additional information is superimposed. It becomes possible.

According to the present invention, an increase in the amount of information is minimized, and efficient transmission of additional information is performed, as compared with the case where the embedding patterns according to a plurality of encoding systems / encoding formats are simultaneously multiplex-superimposed. Becomes possible. Further, when a digital watermark is used for the encoding means, deterioration of image quality can be minimized.

Further, by encoding the same additional information by a plurality of encoding means and embedding it in the main information signal,
Even if one of the additional information is deteriorated due to signal processing, an attack, or other causes, the additional information can be accurately detected based on the other additional information.

Further, according to the additional information embedding apparatus and method according to the present invention, by using a plurality of encoding methods / formats, even if the additional information is information important for security, all the information can be used. Unless the encoding method is broken, security information cannot be completely erased, falsified, or disabled. Also, in the unlikely event that additional information is attacked, a new encoding method / format is newly introduced in the future, and further multiplexed or time-division multiplexed and embedded in the main information signal to ensure the transmission of information. It is possible to do.

Conventionally, when there are a plurality of methods / systems for encoding additional information relating to copy protection, and when the information is separately implemented (separately superimposed on the information signal), the detector is set to the code. Unless the number of formats / formats is prepared, reliable copy protection cannot be performed. On the other hand, according to the present invention, since the additional information is time-division multiplexed, it is possible to detect the additional information only by having at least one or more detectors from among the additional information. Copy protection.

Still other objects, features and advantages of the present invention are:
It will become apparent from the following more detailed description based on the embodiments of the present invention and the accompanying drawings.

[0040]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the present specification, as an additional information embedding device, the present invention is applied to a system in which an additional information signal is encoded by two kinds of encoding methods and time-division multiplexed and superimposed on an output video signal from a recording medium on which a video signal is recorded. This embodiment will be described as an example.

FIG. 1 schematically shows a functional configuration of an additional information embedding device 100 used for carrying out the present invention. The additional information embedding device 100 can encode an additional information signal by two types of encoding schemes, generate respective embedding patterns, and superimpose these embedding patterns on a video signal while performing time division multiplexing.

As shown in the figure, the additional information embedding device 100 includes a recording medium 101 on the video signal reproducing side, a data input unit 102, a first encoding unit 104, and a second encoding unit 105. , The time division multiplexing unit 106 and the superimposing unit 1
07.

A read signal obtained by reproducing the recording medium 101 is supplied to the data input unit 102 and output to the superimposing unit 107 as a video reproduction signal.

Further, additional information to be embedded in the video signal is supplied to each of the first encoding unit 104 and the second encoding unit 105.

The first encoding unit 104 has a key Key1 for encoding, and uses Key1 to encode the additional information according to a first encoding method.
The time-division multiplexing unit 10 as the first embedding pattern signal
6 is output.

Further, the second encoding unit 105 has a key Key2 for encoding, and the first encoding method applied by the first encoding unit 104 using Key2 is as follows. The additional information is encoded by a different second encoding method and output to the time division multiplexing section 106 as a second embedded pattern signal. Key2 used for encoding is Ke
It may be the same or different from y1.

The time division multiplexing section 106 multiplexes the first embed pattern signal and the second embed pattern signal supplied from each of the first encoding section 104 and the second encoding section 105 by time division multiplexing. And outputs the result to the superimposing section 107.

The superposition unit 107 combines the video signal read from the recording medium and the time-division multiplexed embedded pattern signal, and outputs it as an output video signal with additional information.

This output video signal is output to, for example, a recording medium 151 on the recording side different from the recording medium 101 on the reproducing side.
Recorded in the device and moved to another device. Alternatively, the output video signal may be transmitted to a remote device via the network 152.

FIG. 2 shows an example of a functional configuration of an additional information detecting device 200 for detecting additional information from a video signal containing additional information. It is assumed that the additional information detection device 200 can detect an embedded pattern signal encoded by the first encoding method adopted by the first encoding unit 104.

As shown in FIG.
0 includes a recording medium 201 storing a video signal containing additional information, a data input unit 202, and an encoding unit 203.

A read signal obtained by reproducing the recording medium 201 is supplied to a data input section 202 and output to a decoding section 203 as a video reproduction signal.

The decoding section 203 decodes the input video reproduction signal. The decoding unit 203 is configured to perform only the decoding process corresponding to the first coding scheme adopted in the first coding unit 104 using the same key Key1. Therefore, decoding section 203 can detect only the additional information encoded by first encoding section 104.

FIG. 3 shows an example of the functional configuration of an additional information detecting device 200 'for detecting additional information from a video signal containing additional information. The additional information detecting device 200 '
Can detect an embedded pattern signal encoded by the second encoding method adopted by the second encoding unit 105.

As shown in FIG.
0 ′ is a recording medium 201 ′ storing a video signal containing additional information, a data input unit 202 ′, and an encoding unit 20 ′.
3 ′.

A read signal obtained by reproducing the recording medium 201 ′ is supplied to a data input unit 202 ′,
The video reproduction signal is output to the decoding unit 203 '.

The decoding section 203 'decodes the input video reproduction signal. The decoding unit 203 ′ is configured to perform only the decoding process corresponding to the second coding scheme adopted in the second coding unit 105 using the same key Key2. Therefore, the decoding unit 20
In 3 ′, only the additional information encoded by the second encoding unit 105 can be detected.

On the side of additional information embedding apparatus 100, when both first encoding section 104 and second encoding section 105 handle the same additional information, that is, encode the same additional information by changing the encoding method. In the case where the video signal is subjected to a time-division multiplexing process (into another embedded pattern signal) and time-division multiplexed and inserted into a video signal, the additional information detection device 200/200 'side corresponds to one of the encoding methods. If only the decoding process is performed, the original additional information can be detected.

The embedding pattern signals encoded by the respective encoding methods may be encoded so as to be orthogonal or non-correlated with each other. For example, in the case where additional information is encoded using a digital watermark, erroneous detection can be prevented by encoding the additional information independently or orthogonally.

The encoding system used in each of the encoding units 104 and 105 may be digital watermarking, steganography, encryption, or the like, or may be a combination of two or more encoding systems. A method of encoding the additional information and inserting it into the main information signal is described in, for example, Japanese Patent Application Laid-Open No. 9-163341 (US Pat. No. 5,982,997) and US Pat.
And US Pat. No. 5,848,155.

Although two encoding units 104 and 105 are provided in FIG. 1, three or more encoding units are mixed, and three or more embedded pattern signals are time-division multiplexed. And inserted into the main information signal.

On the side of detecting the additional information, it is not always necessary to prepare a plurality of detectors 200/200 'corresponding to each encoding system as shown in FIGS. 2 and 3, for example. You may make it use only.

Further, in the additional information embedding apparatus 100, the additional information supplied to each of the encoding units 104 and 105 may be exactly the same, or different additional information or only a part of the additional information may be changed or added in some cases. The additional information may be supplied to the respective encoding units 1041 and 105.

The intervals at which the respective pieces of additional information are multiplexed and superimposed in the time division multiplexing section 106 and the superimposing section 107 are as follows.
Each frame may be used, or a multiple of two frames (24
P), or a multiple of five fields (60i), or about 10 seconds or more.

The main information signal on which the additional information is superimposed is not limited to the video signal described above, but may be a signal other than video, such as an audio signal or a text signal. Further, the recording medium may be a disk medium such as a DVD, or may be a DVHS or DV.
May be a tape medium such as.

Further, the additional information detecting device is a DVD, DV
It may be a digital video recording device such as an HS or a DV, or a combination of a personal computer and a media drive mounted on the personal computer. The movement of the main information signal and the information signal containing the additional information may be performed via a network or a broadcast wave instead of the recording medium.

The additional information may be copy control information relating to data / content serving as main information, or may be other information.

FIG. 4 illustrates a configuration example of a code modulation device used for encoding and decoding processes in the additional information embedding device and the detection device shown in FIG. 1, and FIGS. 2 and 3.

The modulator shown is also an example of an embedding pattern generation circuit applied to a digital watermarking technique. In other words, the embedding pattern is changed to the PN (Pseudorandom Noisy) in accordance with the 1 V cycle of the video signal by the spread spectrum.
e: a pseudo-noise code) generated by a generating circuit to spread the additional information. At the time of detection, the video signal is despread to detect additional information.

In the figure, the modulation device has 409 per 1 V section.
This is an example of a buried pattern generation circuit when five chips are inserted.

If the clock rate is about 250 KHz, one cycle of the embedding pattern is 4095/250 =
16.38 msec, almost 1V section (= 16.7)
msec = 1/60 sec).
At this time, by inputting the reset signal to the initialization signal every 1 V, the phase of the embedded pattern code can be aligned with respect to the 1 V cycle. This makes it possible to generate an inspection embedding pattern by synchronizing the embedding patterns and detect information embedded in the information signal. Here, 1 V corresponds to one field of the video signal. In addition, it is also possible to set every frame.

FIG. 5 schematically shows a functional configuration of an additional information embedding device 100 ′ according to another embodiment of the present invention. This additional information embedding device 100 ′
The additional information signal can be encoded by two types of encoding schemes to generate embed patterns, and these embed patterns can be multiplexed and superimposed on the video signal.

The additional information embedding device 100 shown in FIG.
In FIG. 5, a plurality of embedding patterns are time-division multiplexed, that is, different patterns are superimposed at predetermined intervals in the time direction of a video signal, whereas in the additional information embedding apparatus 100 ′ shown in FIG. Each of the embedding patterns is multiplexed by a method other than the above, and is superimposed on the video signal.

In this embodiment, multiplexing methods other than time division, such as "spatial multiplexing", "frequency multiplexing", and "overwrite multiplexing", can be adopted.

Here, the spatial multiplexing is a method in which a region such as each frame or each field of a video signal is spatially divided into two (or a plurality) and multiplexed. Alternatively, multiplexing may be performed by dividing into small blocks or pixels.

In the case of time division multiplexing, the time when additional information can be detected and the time when additional information cannot be detected are mixed in one additional information detecting device. On the other hand, according to spatial multiplexing, the range in which each embedding pattern is embedded is limited, but there is no section in which a certain embedding pattern cannot be detected. However, in spatial multiplexing, since a plurality of embedding patterns are embedded in one frame or one field by dividing the area,
The detection time becomes longer according to the number of embedding patterns to be multiplexed.

In frequency multiplexing, a video signal is divided into a plurality of frequency bands on a Fourier transform or a DCT (Discrete Cosine Transform) coefficient, and the divided signal is made to correspond to each divided frequency band. This is a method of multiplexing each embedding pattern. It is possible to eliminate a section in which a certain embedding pattern cannot be detected even by frequency multiplexing. However, the detection time is longer than in time division multiplexing.

The overwriting multiplexing is a method of overwriting a plurality of embedding patterns, and may be performed in combination with frequency multiplexing, in addition to performing complete overwriting. It is possible to eliminate a section in which a certain embedding pattern cannot be detected even by overwriting multiplexing. In the overwriting multiplexing, in order to make it possible to detect an embedding pattern embedded in the same area, embedding is performed using Key1 and Key2 having different values. When detecting, Key1 and K
Each embedding pattern can be detected using the decorrelation of ey2. Also, Ke having the same value
Although y1 and Key2 are used, they can be detected from the same area of each embedding pattern by embedding with different phases. Further, by performing multiplexing while reducing the embedding level using the reciprocal of the embedding pattern to be overwritten, it is possible to prevent deterioration of the quality (image quality, sound quality, etc.) of the main information signal. The amount of information remains unchanged.
However, the detection time becomes longer.

As shown in FIG. 5, the additional information embedding device 100 ′ according to this embodiment includes a recording medium 101 on the video signal reproducing side, a data input unit 182, a first encoding unit 184, and a second encoding unit 184. Encoding unit 185 and the multiplexing unit 18
6 and a superimposing unit 187.

A read signal obtained by reproducing the recording medium 101 is supplied to a data input section 182 and output to a superimposing section 187 as a video reproduction signal.

Further, additional information to be embedded in the video signal is supplied to each of first encoding section 184 and second encoding section 185.

The first encoding unit 184 has a key Key1 for encoding, and uses Key1 to encode the additional information using the first encoding method.
Output to multiplexing section 186 as a first embedded pattern signal.

Further, the second encoding unit 185 has a key Key2 for encoding, and uses Key2 in a second encoding method different from that of the first encoding unit 184. The additional information is encoded and output to multiplexing section 186 as a second embedded pattern signal. Key2 used for encoding may be the same as or different from Key1.

The multiplexing unit 186 includes the first encoding unit 18
4 and the first encoder 185 supplied from each of the second encoders 185.
And the second embedding pattern signal are multiplexed and output to the superimposing section 107. To multiplex a plurality of embedding patterns, spatial multiplexing, frequency multiplexing, overwrite multiplexing, and the like can be applied (described above).

The superimposing section 187 combines the video signal read from the recording medium and the multiplexed embedded pattern signal, and outputs it as an output video signal with additional information.

This output video signal is output to, for example, a recording medium 151 on the recording side different from the recording medium 101 on the reproducing side.
Recorded in the device and moved to another device. Alternatively, the output video signal may be transmitted to a remote device via the network 152.

In order to detect the additional information from the video signal into which the additional information is inserted by the additional information embedding apparatus 100 'according to this embodiment, for example, the additional information detecting apparatus 200/200' shown in FIGS. 2 and 3 is used. Can be applied.

[Supplement] The present invention has been described in detail with reference to the specific embodiments. However, it is obvious that those skilled in the art can modify or substitute the embodiment without departing from the scope of the present invention.

In this specification, as an additional information embedding device, the present invention is applied to a system in which an additional information signal is encoded into an output video signal from a recording medium on which a video signal is recorded by two types of encoding methods and multiplexed. Although the embodiment has been described as an example, the gist of the present invention is not necessarily limited to this. For example, the present invention can be similarly applied to a case where information signals other than video signals such as audio signals and text signals are handled. In addition, not only when recording and reproducing information signals on a recording medium,
The present invention can be similarly applied to a case where an information signal is transmitted via a transmission medium.

In short, the present invention has been disclosed by way of example, and should not be construed as limiting.
In order to determine the gist of the present invention, the claims described at the beginning should be considered.

[0091]

As described above in detail, according to the present invention,
It is possible to provide an excellent additional information embedding apparatus and method capable of suitably embedding additional information in a main information signal such as an image or music in a form almost invisible or inaudible.

Further, according to the present invention, an embedding pattern encoded by a plurality of types of encoding formats having different encoding systems and encoding keys can be detected in any encoding system / encoding format. An excellent additional information embedding apparatus and method capable of embedding additional information in a main information signal can be provided.

In the additional information embedding apparatus and method according to the present invention, the additional information is separately encoded by two or more different encoding systems / encoding formats, and the embedding pattern encoded by each system is multiplexed or Since it is time-division multiplexed and superimposed on the main information signal,
By performing decoding according to at least one of the encoding methods / formats, it is possible to detect additional information.

According to the present invention, an increase in the amount of information is minimized, and the transmission of the additional information is minimized, as compared with the case where the embedding patterns according to a plurality of encoding systems / encoding formats are simultaneously multiplex-superimposed. Becomes possible. Further, when a digital watermark is used for the encoding means, deterioration of image quality can be minimized.

Also, by encoding the same additional information by a plurality of encoding means and embedding it in the main information signal,
Even if one of the additional information is degraded due to signal processing, an attack or the like, the additional information can be accurately detected based on the other additional information.

According to the additional information embedding apparatus and method according to the present invention, by using a plurality of encoding methods / encoding formats, even if the additional information is information important for security, all the information can be used. Unless the encoding method is broken, security information cannot be completely erased, falsified, or disabled. Also, even if the additional information is attacked,
By introducing another encoding method / format newly, and further multiplexing and embedding it in the main information signal, it is possible to transmit information reliably.

Conventionally, when there are a plurality of systems / encoding formats for encoding additional information relating to copy protection, they are separately implemented (separately superimposed on information signals)
In such a case, reliable copy protection could not be performed unless detectors were prepared by the number of encoding systems / encoding formats. On the other hand, according to the present invention, since the additional information is multiplexed, it is possible to detect the additional information only by having at least one or more detectors from among the multiplexed information.・
Protection can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a functional configuration of an additional information embedding device 100 provided for implementing the present invention.

FIG. 2 is a diagram illustrating a functional configuration example of an additional information detection device 200 that detects additional information from a video signal containing additional information.

FIG. 3 is a diagram illustrating an example of a functional configuration of an additional information detection device 200 ′ that detects additional information from a video signal containing additional information.

FIG. 4 is a diagram illustrating a configuration example of a code modulation device used for encoding and decoding processing.

FIG. 5 is a diagram schematically showing a functional configuration of an additional information embedding device 100 ′ according to another embodiment of the present invention.

[Explanation of symbols]

 100, 100 '... additional information embedding device 101 ... (reproducing side) recording medium 102, 182 ... data input unit 104, 184 ... first encoding unit 105, 185 ... second encoding unit 106 ... time division multiplexing Units 107, 187 Superimposing unit 186 Multiplexing unit 200, 200 'Additional information detecting device 201, 201' Recording media 202, 202 'Data input unit 203, 203' Decoding unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/387 G10L 9/00 E 7/081 F term (Reference) 5B057 AA20 CA01 CA08 CA12 CA16 CB01 CB08 CB12 CB16 CC03 CE08 CG05 5C063 AB07 CA23 CA34 CA36 DA07 DA13 EB01 EB04 5C076 AA14 BA06 BA09 5J104 AA14 5K022 CC00

Claims (20)

[Claims] 1. An additional information embedding device for superimposing additional information on a main information signal, comprising: a generating means for generating a first embedded signal from the additional information and generating a second embedded signal from the additional information; Superimposing means for superposing each embedding signal generated by the generating means on the main information signal. 2. The apparatus according to claim 1, wherein the superimposing means includes a first section in which the first embedded signal is superimposed on the main information signal and a second section in which the second embedded signal is superimposed on the main information signal. The additional information embedding device according to claim 1, wherein the first embedding signal and the second embedding signal are superimposed on the main information signal so that the information signal appears repeatedly in the time direction. 3. The superimposing means embeds different embedding signals in the main information signal at predetermined time intervals.
3. The additional information embedding device according to claim 2, wherein: 4. The additional information embedding device according to claim 2, wherein said superimposing means embeds different embedding signals in said main information signal for each of a predetermined number of frames or a predetermined number of fields. 5. The superimposing means superimposes the first embedding signal and the second embedding signal on a plurality of regions obtained by dividing a signal unit constituting the main information signal. Item 2. The additional information embedding device according to Item 1. 6. The additional information embedding according to claim 3, wherein the main information signal is a video signal, and a signal unit of the main information signal is a frame or a field constituting the video signal. apparatus. 7. The additional information embedding apparatus according to claim 1, wherein said generating means generates the first embedded signal and the second embedded signal from the same additional information. 8. The method according to claim 1, wherein the generating means generates the first embedded signal and the second embedded signal using key information, and generates a different embedded signal from the additional information due to a difference in key information to be used. 2. The additional information embedding device according to claim 1, wherein: 9. The additional information embedding apparatus according to claim 1, wherein said generating means generates different embedding signals from the same additional information due to a difference in encoding method. 10. A method for embedding additional information in a main information signal, the method comprising: generating a first embedded signal from the additional information; and generating a second embedded signal from the additional information. A superimposing step of superimposing each embedding signal generated in the generating step on the main information signal. 11. The superimposing step comprises the steps of: a first section in which the first embedded signal is superimposed on the main information signal; and a second section in which the second embedded signal is superimposed on the main information signal. As it appears repeatedly in the time direction of the information signal,
The method according to claim 10, wherein the first embedding signal and the second embedding signal are superimposed on the main information signal. 12. The additional information embedding method according to claim 11, wherein said superimposing step includes embedding different embedding signals in said main information signal at predetermined time intervals. 13. The main information signal according to claim 11, wherein the embedding step includes embedding different embedding signals for each of a predetermined number of frames or a predetermined number of fields in the main information signal.
Additional information embedding method described in. 14. The superimposing step, wherein the first embedding signal and the second embedding signal are superimposed on a plurality of regions obtained by dividing a signal unit constituting the main information signal.
The method for embedding additional information according to claim 10, wherein: 15. The embedding of additional information according to claim 12, wherein the main information signal is a video signal, and a signal unit of the main information signal is a frame or a field constituting the video signal. Method. 16. The additional information embedding method according to claim 10, wherein said generating step generates the first embedded signal and the second embedded signal from the same additional information. 17. The method according to claim 17, wherein the generating step generates the first embedded signal and the second embedded signal by using key information, and generates a different embedded signal from the additional information due to a difference in key information to be used. The method for embedding additional information according to claim 10, wherein: 18. The method according to claim 18, wherein the generating step generates different embedded signals from the same additional information due to a difference in encoding method.
The method for embedding additional information according to claim 10, wherein: 19. A recording medium on which a signal in which additional information is superimposed on a main information signal is recorded, wherein a first embedded signal generated from the additional information and a second embedded signal generated from the additional information are recorded. A recording medium on which a signal multiplexed and superimposed on a main information signal is recorded. 20. A recording medium on which a signal in which additional information is superimposed on a main information signal is recorded, wherein a first embedding signal is generated from the additional information and a second embedding signal is generated from the additional information. A superimposing step of superimposing each embedded signal generated in the generating step on a main information signal; and a recording step of recording a signal in which each embedded signal generated in the superimposing step is superimposed on a recording medium. Recording medium characterized by being performed.