JP2000082258A - Data reproduction device - Google Patents

Abstract

(57) [Summary] [Object] The object of the present invention is to detect data transmitted by adding information such as copy prohibition to image or audio data.
This means keeping the detection circuit small. In order to achieve the above object, according to the present invention, first data which is image or audio information and second data which is additional information of the first data are embedded in the first data. A reproduction processing means for reproducing and processing the first data, a detection means for detecting the second data embedded in the first data, and controlling an output of the data reproduced by the reproduction processing means. Output control means, and the detection means is achieved by performing detection between the reproduction processing means and the output control means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to image data and audio data which have different data (data hiding, watermark).
More particularly, the present invention relates to a recording and reproducing apparatus including an LSI having a function of detecting embedded data.

[0002]

2. Description of the Related Art A digital watermarking technique (data hiding) has been studied so far as a technique for embedding identification information and annotations in image, voice and text data. Recently, identification information has been embedded in data to protect copyrights, and has been applied as a technique for preventing unauthorized operations. These techniques are described in "Nikkei Electronics" of Nikkei BP (1997.24. P149-P162).

Since data to be embedded is deteriorated by operations such as filtering and data compression, it may be removed after conversion. For this reason, data is repeatedly embedded so that the data is not removed.

[0004]

Various situations are conceivable with respect to copy restrictions, such as original data that can be freely copied due to copyright, data that is prohibited from being copied, and data that can be copied only once. It has been considered that data is embedded using a digital watermarking technique in accordance with those situations, and copying is controlled by detecting the data.

The data to be embedded is always embedded in the original data so that it can be detected even if any part of the data is reproduced.

However, there is no description of the operation of a system having a function of detecting data embedded in this way. Further, the document does not describe the configuration of a system having a function of detecting embedded data.

When the function of detecting embedded data is configured by hardware, the circuit scale varies greatly depending on the configuration. Therefore, it is an issue to construct an appropriate system.

[0008]

In order to achieve the above object, according to the present invention, the first data which is information of an image or a sound and the second data which is additional information of the first data are the same. Reproduction processing means for reproducing and processing the first data embedded in the first data, detection means for detecting the second data embedded in the first data, and reproduction by the reproduction processing means Output control means for controlling the output of the output data, wherein the detection means performs detection between the reproduction processing means and the output control means, thereby constructing a system for detecting embedded data.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of the operation of a system having a digital watermark detection function according to the present invention. Also,
FIG. 2 shows an embodiment of the configuration of a system having a digital watermark detection function according to the present invention.

Here, for the sake of explanation, an example of a disk reproducing apparatus will be used, but this is, of course, not limited to a disk reproducing apparatus, but relates to a general data recording / reproducing apparatus including a magnetic recording / reproducing apparatus.

Here, a case is considered where the type of embedded data is information for copy control. of course,
The information to be embedded is not limited to copy control information, but is not limited to digital information such as information indicating the type of data and control information corresponding to each recording medium.

In order to reproduce data written on a recordable recording medium such as a CD-R or a DVD-R, copy control may be required for copyright protection. Therefore, it is necessary to detect copy control information recorded on the disc and perform reproduction control or recording control accordingly.

In FIG. 2, 11 is a disk as a recording medium, 12 is a pickup, 13 is a preamplifier, 14 is a signal processing LSI, 15 is a reproduction signal processing means, 16 is copy control information detecting means, 17 is output control means, Reference numeral 18 denotes a signal output, and 19 denotes a system control unit.

A signal reproduced from the disk 11 by the pickup 12 is amplified by a preamplifier 13 and input to a signal processing LSI 14. The signal processing LSI 14 is roughly divided into a reproduction signal processing unit 15 for performing reproduction processing according to a format in which a reproduction signal is recorded, a copy control information detection unit 16 for detecting copy information included in the reproduced signal, If the copy information is copy prohibited, the output control means 17 does not output the output signal 18. Of course, if the copy is not prohibited, it is not necessary to stop the output. Therefore, the data processed by the reproduction signal processing means 15 is output to the output control means 17.
And output while adjusting the transfer format of the output and controlling the timing. These are, for example, when the signal output 18 is connected to a PC, SCSI, ATAPI, IEEE1
394, USB and other buses are conceivable. System control means 1
In the step 9, once the copy control information detecting means 16 detects once, the detecting operation is stopped for a predetermined time, for example, N seconds, and the detecting operation of the copy control information detecting means 16 is performed again after N seconds. Further, the system control means 19 is provided with the reproduction signal processing means 1
In step S5, an ID or track number indicating the attribute of the data is received from the management information of the data reproduced in step 5, and if the recording data is discontinuous, the copy control information detecting means 16 is operated to detect it.

As described above, the copy control information detecting means 16
Detection by the reproduction signal processing means 15 and the output control means 17
That is, the copy control information detecting means 16 receives a reproduction signal suitable for detecting copy control information, performs detection processing, and performs output control according to the result of the detection processing. By doing so, a circuit or the like serving as a reproduction signal processing means can also be used without separately providing a circuit or the like for processing a signal for detecting copy information, and the circuit scale can be reduced.

Here, the signal processing LSI 14 outputs the data from the output control means 17 after the reproduction signal processing means 15 performs demodulation and error correction, that is, as in the case of the DVD drive system shown in FIG. In the case of a system without a decoder, data after error correction is output. Further, although not shown in FIG. 2, the signal processing LSI 14 is not limited to the demodulation and error correction, and is not limited to an MPEG decoder in the case where the recorded data is image data compressed by MPEG and includes an MPEG decoder. Outputs the decoded (decompressed) data.

As shown in FIG. 1, when a new disc is inserted or when reproduction is started, it is necessary to detect copy control information of data written on the disc and perform control. Judge whether or not. Since it is not necessary to constantly detect the copy control information, once the copy control information is detected, the detection operation may be stopped for a predetermined time. Here, for example, the operation is stopped for N seconds, and the detection is performed again after N seconds, and it is confirmed that the result matches the result detected earlier. If they match, the detection operation is stopped again.

By intermittently controlling the operation as described above, it is possible to reduce the power consumption of the detecting means.

On a writable disc, data can be added as several files, and copy control information may be different for each file. Therefore, when the head of the file is newly detected, the detection operation is restarted even if the detection operation is stopped. Thereby, even when files of different copy control information coexist on the same disk, copy control can be performed correctly.

Considering the case where the recording medium is a VTR, a signal indicating a recording start position such as a VISS signal may be recorded on the VTR. When this is detected, the detection operation is similarly started. To do it.

In order to stop the operation of the copy information detecting means, the power consumed by the detecting means is suppressed by a method such as stopping the operation clock or continuously giving a reset signal.

FIG. 3 shows an embodiment of a processing method for embedding copy information in image data. One natural image is replaced as digital data, and in order to embed the copy information in the digital image, 8 ×
It is divided by a square pixel block of 8 pixels. One of the pixels is replaced with 64 pieces of data having a fixed number of bits. If the data is 8-bit data, the data has 512 levels of resolution.

If the pixel block is a point where transmission data is embedded, processing is performed according to the value of each bit of the transmission data. For example, when the bit of the transmission data embedded at that point is “1”, the data value is converted so that the sum of the 64 pixel data is a multiple of 512, and (a0 + a1 + a2 +... + a63) mod 512 = 0 (mod indicates the remainder of division) If the bit is “0”, the sum of 64 pixel data is set to 256, which is a multiple of 512 (a0 + a1 + a2 + · ... + A63) mod 512 = 256 The values of data a0 to a63 are converted. The value of 512 (and 0, 256) used in this case is not particularly limited, but a larger value means that the original data is largely converted instead of being easy to determine and reducing errors. Become.

When embedding transmission data, 5
It is also possible to convert the data value so as to be in the range of 12 ± α (eg, α = 64).

In this manner, 64 pixels of one pixel block are used.
The pixel data is converted, and the transmission data is divided into bits and embedded.

If these transmission data are compressed / expanded after being embedded, they may not be accurately reproduced. In consideration of such a case, the determination of transmission data after reception is not limited to (a0 + a1 + a2 +... + A63) mod 512 = 0, but 0 ± α (α is a compression method. Α determined from etc.
≤64).

Here, an example in which the transmission data is embedded in the sample value has been described. However, it is also possible to embed the transmission data in a frequency-converted value such as DCT or FFT.

FIG. 4 shows an example of points for embedding transmission data in one whole natural image. The transmission data is embedded at (n + m) × P points in the image data.

At the time of reproduction, P b0 bits are collected from the embedding point of b0, and a majority decision is made. This is performed for n + m bits to obtain the transmission data after the majority decision.
By repeatedly embedding each bit of the transmission data at a plurality of points in this way, it is possible to make a majority decision at the time of reproduction and to correctly reproduce the information bits. By embedding in this way, it is possible to always embed in data, and it is possible to detect copy information regardless of where data is reproduced.

Further, another different embedding pattern is determined, and different copy information is applied to it. For example, different copy information can be allocated such that one pattern is copy-prohibited and another pattern can be copied only once. By detecting these patterns, it is possible to detect how the data is copy-restricted.

When embedding copy information, for example, when embedding information that can be copied only once,
The data can be copied only once. Then, it is necessary to additionally embed or rewrite the copy-prohibited information indicating that the data copied once should not be copied any more. At this time, the data in which the copied original data is embedded is information that can be copied only once and cannot be removed. Therefore, the copy prohibition information is additionally embedded. When this data is reproduced. Two types of information, that is, information indicating that copying is allowed only once and information indicating that copying is prohibited, are detected. In this case, leave the priority decision information indicating to adopt either advance information, if only two types of information: information that can be copied that information and the copy inhibition is detected, for example, once, the copy inhibition Decide to adopt information. As described above, by adding and embedding information and performing control based on priority at the time of detection, information can be rewritten.

FIG. 5 shows another embodiment of the configuration of a system having a digital watermark detection function according to the present invention. Those having the same numbers as those in FIG. 2 indicate the same ones.

The signal reproduced from the disk 11 by the pickup 12 is amplified by the preamplifier 13 and input to the signal processing LSI 14. The signal processing LSI 14 is roughly divided into a reproduction signal processing unit 15 for performing a reproduction process according to a format in which a reproduction signal is recorded, a copy information detection unit 17 for detecting copy information included in the reproduced signal, If the copy information indicates that copying is prohibited, the output control means 17 does not output an output signal. Once the copy information detecting means 17 performs the detection, the detecting operation is stopped for a predetermined time, for example, N seconds, and the detecting operation of the copy information detecting means 17 is performed again after N seconds. This operation can be easily configured by providing a counter inside. Further, the reproduction signal processing means 15 reproduces an ID or a track number indicating the attribute of the data from the management information of the reproduced data, and when the recorded data is discontinuous, the copy information detecting means 17 performs a re-detection operation. The detection operation is performed by issuing an instruction to perform the operation.

By intermittently controlling the operation in this way, it is possible to reduce the power consumption of the detecting means.

As is clear from FIG. 5, the signal processing LSI 14 has a structure in which the inside of the signal processing LSI 14 is not easily modified, thereby making it difficult to falsify. The signal processing LSI 14 outputs data after performing decompression processing when outputting data after demodulation and error correction, and when recorded data is image data compressed by MPEG. There are cases.
In any case, a single LSI can prevent system falsification.

[0037]

According to the present invention, the detection by the copy control information detection means is performed between the reproduction signal processing means and the output control means, that is, the reproduction signal suitable for detecting the copy control information is copied. The detection means receives and performs the detection processing, and the output control means controls the output according to the result of the detection processing, so that the reproduction can be performed without a separate circuit for processing a signal for detecting copy information. A circuit or the like serving as a signal processing means can be shared, and the circuit scale can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the operation of a system having a digital watermark detection function according to the present invention.

FIG. 2 is a diagram showing an embodiment of a configuration of a system having a digital watermark detection function according to the present invention.

FIG. 3 is a diagram showing an embodiment of a processing method for embedding information bits in image data.

FIG. 4 is a diagram illustrating an example of points at which transmission data is embedded in an entire natural image.

FIG. 5 is a diagram showing another embodiment of the configuration of a system having a digital watermark detection function according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Disc, 12 ... Pickup, 13 ... Preamplifier, 14 ... Signal processing LSI, 15 ... Reproduction signal processing means, 16 ... Copy information detection means, 17 ... Output control means, 18 ... Signal output, 19 ... System control means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) // G09C 5/00 (72) Inventor Taku Hoshizawa 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Hitachi, Ltd. Multimedia System Development Division

Claims (7)

[Claims] A first data which is information of an image or a sound;
Second data, which is additional information of the first data, is embedded in the first data, and reproduction processing means for reproducing and processing the first data and the second data embedded in the first data. (2) detecting means for detecting data and output control means for controlling output of data reproduced by the reproduction processing means, wherein the detection means performs detection between the reproduction processing means and the output control means. Data playback device characterized by the following 2. A data reproducing apparatus according to claim 1, wherein in said reproduction processing, at least demodulation processing and error correction processing are performed, and thereafter detection is performed. 3. The method according to claim 1, wherein said detecting means performs detection before outputting reproduced data from an output terminal of said output control means. Data playback device 4. A data reproducing apparatus according to claim 1, wherein said detection means performs detection immediately before said output control means. 5. A method according to claim 1, wherein the first data is information of an image or a sound.
Second data, which is additional information of the first data, is embedded in the first data, and reproduction processing means for reproducing and processing the first data and the second data embedded in the first data. And a control unit for controlling the output of the data reproduced by the reproduction processing. The detection processing by the detection means is performed by the reproduction processing by the reproduction processing unit and by the output control means. A data reproduction method characterized by performing a detection process during output control. 6. A data reproducing method according to claim 5, wherein in said reproducing processing, at least demodulation processing and error correction processing are performed, and then detection processing is performed. 7. The method according to claim 5, wherein the detection processing by the detection means is performed before outputting the reproduced data from the output terminal of the output control means. Data playback device characterized by the following: