JPH11355735A - Method for imbedding and reproducing digital data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance security by imbedding digital data to moving image data. SOLUTION: When transmission of moving image data in this imbedding and reproduction method is started, frame information 91 of imbedded information 9 of digital data to be imbedded is referred to discriminate whether or not a frame is an imbedded frame, and when the imbedded frame is detected, the digital data are converted according to conversion information 93 and the data are inserted and imbedded in an imbed area designated by position information 92 to imbed the converted digital data. The processing is repeated till all frames are transmitted and the digital data are imbedded to each frame designated by the imbedded information 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for embedding and reproducing digital data for embedding digital data in a moving image and reproducing the embedded data.

[0002]

2. Description of the Related Art For example, a method of embedding digital data in an image for protecting a copyright or the like to enhance confidentiality is disclosed in Japanese Patent Application Laid-Open No. Hei 9-191395. This digital data embedding method modulates the digital data to be embedded with a carrier image to generate a frequency-dispersed data image, and adds the generated data image to a source image to be embedded without visually distorting the image. I try not to lose the contents of the image.

[0003]

However, the above-described method of embedding digital data is an embedding method for still images, and is not an appropriate method for embedding in moving image data. Also, the carrier image needs to be transmitted, and the digital image can be easily restored by eavesdropping, and it is difficult to have confidentiality.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a digital data embedding and reproducing method capable of improving the above disadvantages and embedding digital data in moving image data and having high confidentiality and high security. It is.

[0005]

SUMMARY OF THE INVENTION A method for embedding and reproducing digital data according to the present invention is to transmit, together with digital data, information of a frame of moving image data in which digital data is to be embedded, and embedding information having position information and conversion information to be embedded. At the specified position of the moving image data frame specified by the embedding information, the digital data to be embedded is converted and embedded according to the conversion information, and the digital data dispersed and embedded in the moving image data frame is extracted by the embedding information. It is characterized by reproducing.

[0006] It is preferable that the embedding information designates an embedding position for each frame of a moving image in which digital data is to be embedded. Also, it is preferable to embed the digital data to be embedded by encrypting it.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The digital data embedding method of the present invention is a method of embedding digital data in a predetermined frame when each frame of moving image data is transmitted in frame units. Transmit with the embedded information. The embedding information includes frame information that specifies a frame of moving image data in which digital data is to be embedded, position information that specifies an area of a frame in which digital data is to be embedded, and conversion information that specifies a conversion method of digital data. Then, when the transmission of the moving image data is started, it is determined whether or not the frame is to be embedded by referring to the frame information of the embedding information. When the frame to be embedded is detected, the digital data is converted according to the conversion information, and the position at which the converted digital data is embedded. Insert and embed in the embedding area specified by the information. This process is repeated until all frames are transmitted, and digital data is embedded in each frame specified by the embedding information. When extracting the digital data embedded in the frame of the moving image data, the digital data is reproduced with reference to the embedded information.

[0008]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. As shown in the figure, a data embedding device for embedding digital data in moving image data includes a moving image generation unit 1.
A moving image transmitting unit 2, an embedded information transmitting unit 3, an embedded information storing unit 4, an embedded frame detecting unit 5, a data converting unit 6, an embedding processing unit 7, and an output unit 8. The moving image generator 1 generates digital moving image data. For example, in the NTSC television broadcasting system, horizontal scanning is performed every other line, and
After forming one screen, interlaced scanning is performed to scan the remaining portion of the second screen. A screen formed by one scan is called a field, and a screen completed by two scans is called a frame. The number of frames displayed per second is limited to about 30 frames due to the frequency band. Therefore, the moving image generation unit 1, as shown in FIG.
Fn1, Fn2, and Fn3 are formed at a frame rate of about 30 frames / second. The moving image transmission unit 2 transmits the formed moving image data for each of the frames F0 to Fn3. The embedded information transmitting section 3 transmits digital data and embedded information.
As shown in FIG. 3, the transmission format of the embedding information 9 has frame information 91 of moving image data in which digital data is embedded, position information 92 to be embedded, and conversion information 93. In the frame information 91 of the moving image data to be embedded, the frames in which the digital data is to be embedded are designated at a sufficient interval. The position information 92 to be embedded specifies the area of the frame F in which the digital data is to be embedded.
As shown in the figure, coordinate points (a, b), (a, d), (c, d), (c,
The rectangular area 10 defined by b) is set to a diagonal coordinate point (a,
b), (c, d). This rectangular area 10 is specified to be sufficiently smaller than the size of the entire frame. Conversion information 9
Reference numeral 3 designates whether or not to convert the digital data to be embedded and a conversion method. For example, when the digital data to be embedded is a pattern of image data such as character raster data, the pattern of the original image data can be made invisible by conversion to a random pattern. Hadamard transform can be used as an example of such a transform. The embedded information storage unit 4 stores the transmitted digital data and the embedded information. The embedding frame detecting section 5 includes the embedding information storing section 4
A frame in which digital data is to be embedded is detected from the frame information 91 of the embedding information 9 stored in. The data converter 5 converts the digital data with reference to the conversion information 93 of the embedded information 9. The embedding processing section 6 inserts and embeds digital data into a predetermined frame.

The operation of embedding digital data in moving image data by the data embedding device having the above-mentioned configuration will be described with reference to the flowchart of FIG.

First, digital data and embedding information 9 to be embedded in the embedding information transmission unit 3 are input, and the digital data and the embedding information 9 are transmitted to the embedding information storage unit 4 and stored (step S1). On the other hand, the moving image transmitting unit 2
The frames F0 to Fn3 of the moving image data generated in step (1) are sequentially transmitted in frame units (step S2). When the transmission of the moving image data is started, the embedding frame detecting unit 5 determines whether or not the frame is to be embedded by referring to the information 91 on the frame of the moving image data of the embedding information 9 stored in the embedding information storage unit 4. (Step S3). For example, as shown in FIG. 2, when frames F1, Fn1, F2, and Fn3 are designated as frames to be embedded,
When detecting the frame F1, the embedded frame detection unit 5 instructs the embedding processing unit 7 and the data conversion unit 6 to embed data in the frame F1 (step S4). When the data conversion unit 6 is instructed to embed data in the frame F1, the digital data stored in the embedding information storage unit 4, the position information 92 for embedding the embedding information 9, and the conversion information 9
3 is read, the digital data is converted by the conversion information 93, and the digital data and the position area to be embedded are sent to the embedding processing section 7 (step S5). The embedding processor 7 inserts and embeds the sent digital data into the specified rectangular area 10 of the frame 1 as shown in FIG.
6). This process is repeated until all the frames are transmitted (steps S7, S2 to S6), and as shown in FIG. 1, the frames F1, Fn1,
Digital data is embedded in Fn2 and Fn3. Each frame F in which the digital data is embedded is output from the output unit 8 to a display device, a storage device, or the like.

When the digital data is embedded in the frame F of the moving image data as described above, the rectangular area 10 in which the digital data is embedded is made sufficiently smaller than the entire size of the frame F, and the interval between the frames to be embedded is widened. Visual disturbance to the image can be very small.

When extracting digital data embedded in the frame F of the moving image data, the digital data is reproduced with reference to the embedded information 9. Therefore, a person who does not know the embedded information 9 cannot extract the digital data, and can increase the confidentiality.

In the above embodiment, the digital data is embedded in the same rectangular area 10 specified by the coordinates (a, b) and (c, d) of the frame F of the moving image data, as shown in FIG. First, frame information 9 for each frame of moving image data in which digital data is embedded in the embedding information 9
1a, 91b to 91j and position information 92a, 92 to be embedded
By providing b to 92j, as shown in FIG. 7, frames F1 and
Digital data can be embedded in different rectangular areas 10a to 10j for each of Fn1 to Fnj. By embedding digital data at different positions in each of the frames F1, Fn1 to Fnj, visual disturbance of a moving image can be further reduced.

Further, the digital data to be embedded in the frame of the moving image data is encrypted by an encryption method such as a secret key encryption method or a public key encryption method and stored in the embedded information storage unit 4, and the encrypted digital data is embedded. By doing
Security can be further improved.

[0015]

As described above, according to the present invention, digital data is converted and embedded at a specified position of a frame of moving image data specified by embedding information in accordance with conversion information. It is possible to embed the image with less visual obstruction to the image and to enhance the secrecy of the digital data.

Further, by inserting and embedding digital data at different embedding positions for each frame of a moving image to be embedded, visual disturbance to the moving image can be further reduced.

Further, by encrypting and embedding the digital data, the confidentiality can be further improved and the leakage of the digital data can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a frame of moving image data.

FIG. 3 is a configuration diagram of embedded information.

FIG. 4 is an explanatory diagram showing an embedding area of a frame.

FIG. 5 is a flowchart showing the operation of the embodiment.

FIG. 6 is a configuration diagram of another embedding information.

FIG. 7 is a configuration diagram showing a frame in which digital data is embedded in different areas.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 moving image generation unit 2 moving image transmission unit 3 embedded information transmission unit 4 embedded information storage unit 5 embedded frame detection unit 6 data conversion unit 7 embedded processing unit 9 embedded information 10 rectangular area

Claims (3)

[Claims] 1. A method for transmitting frame information of moving image data in which digital data is to be embedded, embedding information having position information to be embedded and conversion information together with digital data, and specifying a position of a frame of moving image data specified by the embedding information. Digital data to be embedded is converted and embedded in accordance with the conversion information, and the digital data embedded and dispersed in the frame of the moving image data is taken out by the embedding information and reproduced. Embedded playback method. 2. The method of embedding and reproducing digital data according to claim 1, wherein the embedding information designates an embedding position for each frame of a moving image in which digital data is to be embedded. 3. The method of embedding and reproducing digital data according to claim 1, wherein said embedding digital data is encrypted and embedded.