KR101067145B1 - Digital watermarking insertion/extraction apparatus and method, digital rights management system and method using it - Google Patents

Abstract

The present invention relates to a watermarking insertion / extraction apparatus, a method thereof, and a digital rights management system using the same, and a method thereof, which uses digital watermarking technology to forcibly insert user information capable of capturing into digital video content and illegally By detecting user information from the digital video contents in circulation, it is possible to track a user who has illegally captured (/ stored) to impose legal and psychological sanctions on the capture and digitally captured (/ stored) illegally. The present invention provides a watermarking insertion / extraction device and a method thereof, and a digital rights management system using the same, and a method thereof.

To this end, the present invention, in the digital rights management (DRM) system, before the image capture or storage is performed, the user information in each frame of the decompressed video stream (bitmap image) at the time of image playback automatically bit by bit Watermarking inserting means for inserting and watermarking within a video frame playback time; And detecting bit information inserted in each frame of the decompressed video stream (bitmap image) when reproducing the captured or pre-stored distributed image, and reconstructing the user information by combining the detected bit information on a time axis. Watermarking extracting means for showing the information of the user who has captured or pre-stored the image, the watermarking inserting means is to insert the watermarking of the user information to the DC component of the YUV for the bitmap image bitwise The watermarking detecting means detects the inserted bit information on the DC component of the YUV for the bitmap image, and reconstructs the user information by combining the detected bit information on the time axis.

Watermarking, Screen Capture, Digital Rights Management (DRM), Video Players, DirectShow

Description

Watermarking insertion / extraction apparatus and method, and digital copyright management system using same and method therefor {Digital watermarking insertion / extraction apparatus and method, digital rights management system and method using it}             

1 is a configuration diagram of an embodiment of a digital rights management (DRM) system according to the present invention;

2 is a diagram illustrating an embodiment of inserting watermarking information (user information) using a watermarking insertion apparatus (method) according to the present invention;

3 is a diagram illustrating an embodiment of inserting a bit unit of user information into each frame according to the present invention;

4 is a diagram illustrating an example of a process of configuring user information on a time axis of a video in units of bits according to the present invention;

5 is an exemplary diagram illustrating a process of detecting watermarking information (user information) using the watermarking extraction apparatus (method) according to the present invention.

* Explanation of symbols for the main parts of the drawings

10: watermarking inserting device 11,21: source filter                 

12,22: Video Decoder Filter 13: Video Renderer Filter

20: watermarking extraction device 23: watermarking detection filter

The present invention relates to a watermarking insertion / extraction apparatus, a method thereof, and a digital rights management system using the same, and more particularly, to inserting watermarking user information into a video in a digital rights management (DRM) system and capturing the captured information. By extracting watermarking user information from a video file, illegal distribution of digital media content can be prevented and copyright can be protected.

Digital Rights Management (DRM) refers to a function that protects and manages the rights of digital content creators.

Watermarking technology prevents illegal distribution of digital media contents and protects copyrights by inserting information related to copyright on digital contents so as not to be sensibly identified, and claiming copyright infringement.

DirectShow is a COM-based development method provided by DirectX for the expandability and functionality of multimedia playback programs. It is a function that is completed by connecting modules called DirectShow Filter. It is a development method based on Windows operating system.

Windows Media Player is a video playback program provided by MyTrosoft with the Windows operating system and employs the DirectShow method.

Screen capture is a method in which a legal user of a DRM illegally stores a video for a video encrypted by DRM using a capture program such as Capture Solutions. do.

Recently, due to the development of multimedia technology and the rapid spread of wired and wireless Internet, multimedia materials such as images, music, videos, and graphics are mostly distributed as digital media contents. On the other hand, as multimedia materials are distributed through the Internet, digital copyrighted works can be illegally copied and distributed without damage to the original. Such copyright infringement lowers the author's desire to create and commercial damage. Therefore, there is an urgent need for technical solutions that protect copyrights from piracy and distribution along with copyright protection.

In other words, unlike analog content, digital content maintains the same quality as the original even after several copies. When digital content having such characteristics meets the Internet communication media, copies of the same quality as the original can be propagated infinitely rapidly. That's why content owners (e.g., Hollywood filmmakers) who have invested so much capital and effort are reluctant to digitize their content and commercialize it on the Internet. This climate eventually leads to disadvantages in that content consumers (users) cannot receive high quality content.

There are two major copyright protection methods that have been studied or used so far.

The first method is an encryption method, which controls access of content to an arbitrary user and transmits or stores data in an encrypted form. However, this method can be illegally copied and transmitted by using a screen capture method or the like in the case of a video by a user who is allowed to access the decrypted contents once. In addition, in the case of content distributed illegally by such a user, it is virtually impossible to determine which user illegally distributed it.

For this reason, the second method that has recently attracted attention as a solution for copyright protection of multimedia content is digital watermarking, which inserts special information about ownership in a way that is not sensibly well-identified in the content. Is a technology to protect. By inserting user's information into the captured video using this digital watermarking technology, it is expected to prevent illegal distribution of digital content and protect copyrights more efficiently.

Therefore, in the current technical field, digital watermarking technology is used to detect user information from illegally distributed digital video contents by inserting user information that can be captured instead of inserting ownership information into digital video contents. It is essential to provide a way to track the user who has captured the data, to provide legal and psychological sanctions for the capture, and to protect the copyright of illegally captured digital contents.

The present invention has been proposed to meet the above-mentioned requirements, by using digital watermarking technology to forcibly insert the user's information that can be captured in the digital video content, and illegally capture the user information from illegally distributed digital video content A watermarking insertion / extraction device for protecting the copyright of illegally captured (/ stored) digital content by providing a legal and psychological sanction for capturing by allowing the user who performed (/ storing) to be tracked. Its purpose is to provide a method, a digital rights management system using the same, and a method thereof.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

In order to achieve the above object, the present invention provides a watermarking embedding apparatus on a video player, comprising: video decoding means for releasing a compressed video stream using a codec; Watermarking inserting means for automatically inserting user information bit by bit in each frame of the decompressed video stream (bitmap image) during watermark reproduction to watermark within a video frame reproduction time; And video rendering means for reproducing the bitmap image of which the user information is watermarked, wherein the watermarking inserting means is present between the video decoding means and the video rendering means and receives the bit received from the video decoding means. Watermarking the user information is inserted into the DC component of the YUV for the map image bitwise, converted into an RGB bitmap image, and transmitted to the video rendering means.

In another aspect, the present invention provides a watermarking extraction apparatus, comprising: image input means for reading a corresponding image when a captured or pre-stored distributed image is reproduced; Video decoding means for releasing a compressed video stream using a codec; And detecting bit information inserted into each frame of the decompressed video stream (bitmap image), reconstructing user information by combining the detected bit information on a time axis, and capturing or previously storing the corresponding image. And watermarking detecting means for showing information, wherein the watermarking detecting means detects the inserted bits of the DC component of the YUV for the bitmap image received from the video decoding means, and detects the detected bit information on the time axis. In combination to reconstruct the user information to extract information of illegally captured users.

In addition, in the digital rights management (DRM) system, the user information is automatically inserted into each frame of a decompressed video stream (bitmap image) at the time of image reproduction before image capture or storage is performed. Watermarking inserting means for watermarking within a video frame playback time; And detecting bit information inserted in each frame of the decompressed video stream (bitmap image) when reproducing the captured or pre-stored distributed image, and reconstructing the user information by combining the detected bit information on a time axis. Watermarking extracting means for showing the information of the user who has captured or pre-stored the image, the watermarking inserting means is to insert the watermarking of the user information to the DC component of the YUV for the bitmap image bitwise The watermarking detecting means detects the inserted bit information on the DC component of the YUV for the bitmap image, and reconstructs the user information by combining the detected bit information on the time axis.

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The present invention detects user information from illegally distributed digital video contents by inserting information of a user who can be captured (/ stored) instead of inserting ownership information into digital video contents using digital watermarking technology. By providing a method to track users who have illegally captured (/ stored), to impose legal and psychological sanctions on capture (/ storage), and to protect the copyright of illegally captured (/ stored) digital content. do.

The foregoing and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, in which: There will be. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram of an embodiment of a digital rights management (DRM) system according to the present invention.

The service provider and the client system include a microprocessor, a storage means, a communication means, an operating system, and perform a video on demand (VOD) service through a network such as the Internet.

The VOD server is a server or higher computer, and has at least a file server and a streaming server function, and the client system is a personal computer and includes at least a video player (hardware or software module). It is assumed that a device (hardware or software module) capable of capturing a moving image can be installed.

In order to track the user who has done this when the video is captured, illegally copied and distributed by the capturing device (hardware or software module), the watermarking inserting device 10 in the video player of the client system has a watermark before rendering to the screen. The user information is forcibly inserted into the video using a marking technology, and the watermarking extraction device 20 is captured by the capture device (hardware or software module) and illegally distributed as a 'video file with the user information inserted into the watermarking'. Watermarking technology is used to extract illegally captured user information.

Accordingly, the digital rights management (DRM) system according to the present invention includes a watermarking insertion apparatus 10 for forcibly inserting user information (watermarking information) on a client video player, and an image (still image) into which watermarking information is inserted. And a watermarking extraction device 20 for extracting user information (watermarking information) from the video.

More specifically, the digital rights management (DRM) system automatically inserts user information bit by bit into each frame of a decompressed video stream (bitmap image) during video playback before video capture or storage is performed. Watermarking inserting device 10 for watermarking within the frame playback time, and the bit information inserted in each frame of the decompressed video stream (bitmap image) during the playback of captured or pre-stored and distributed image, By combining the information on the time axis to reconstruct the user information, it includes a watermarking extraction device 20 showing the information of the user who captured or pre-stored the image.

The video player for applying the watermarking insertion device 10 is, for example, a player implemented in a "DirectShow" based filter method of "Microsoft", and is connected and operated in the form of a filter graph. Accordingly, the watermarking inserting apparatus 10 inserts user information into the video while the image is played back in the step before capture or storage is performed based on DirectShow technology.

The watermarking insertion apparatus 10 inserts the user information into the video image in real time during the playback process after the encrypted data by the DRM is decoded, and the video player which operates in the client system used by the user. ) (In hardware or software module) to insert user information into the video in real time. At this time, the user information is read from the server through the network or extracted using the record of the client system, and then the information is reproduced using the watermarking inserting device 10 composed of a DirectShow-based filter. Insert it.

In the present invention, the watermarking function of inserting user information into a video exists as a module (hardware or software module) and occupies a part of the video player. That is, the watermarking inserting device 10 for inserting user information into a video may be inserted into an existing video player and upgraded to a video player that can insert user information, or may be integrated with other functions required for video play to provide a new video player. I can make it. In general, although there are many kinds of video players using various methods, the watermarking inserting apparatus 10 of the present invention is based on the DirectShow technology of Microsoft Corporation and is included in a filter graph. Since it acts as an insertable filter, it can be more preferably applied to a video player developed based on DirectShow technology. However, the watermarking inserting apparatus 10 of the present invention should be forcibly executed regardless of the user's intention on the video player, and the existing video player without the watermarking inserting apparatus 10 may be used to display the video content. Since it should not be able to play, it is meaningful to be linked with DRM (Digital Right Management) technology.

2 is a diagram illustrating an embodiment of inserting watermarking information (user information) using a watermarking insertion apparatus (method) according to the present invention.

As shown in FIG. 2, a video player based on DirectShow technology plays multimedia data through filters called filter graphs, and generally includes a source filter 33 and audio / video. It is connected to and operated by a decoder filter (Audio / Video Decoder Filter) (34, 11), an audio / video renderer filter (Audio / Video Renderer Filter) (35, 13).

Here, the source filter 33 reads the media stream from the local file 32 or the VOD server 31 of the network, and the decoder filters 34 and 11 are compressed. It decompresses media information by selecting an appropriate codec. In addition, the renderer filters 35 and 13 play a role of reproducing the decompressed bitmap image or audio data through the reproducing apparatus.

In the present invention, the watermarking insertion filter 12 is positioned between the video decoder filter 11 and the video renderer filter 13 on the filter graph so that the watermarking insertion filter 12 is compressed after the decoder filter 11 before the reproduction and capture of the image is performed. Since the user information is inserted into each frame of the released video by applying a watermarking technique, it is possible to extract the captured image.

The watermarking insertion filter 12 is manufactured in the form of a filter so that when the media starts playing, the watermarking insertion filter 12 is automatically connected to an appropriate point in the filter chain to insert watermarking information, and the Merit value used in the DirectShow filter is increased. By setting it, the existing DirectShow-based video player first selects the filter and inserts user information into the filter graph.

In summary, the watermarking embedding apparatus 10 on a video player based on DirectShow technology includes a video decoder filter for releasing a compressed video stream using a codec suitable for playing the video. 11) a watermarking insertion filter 12 for automatically inserting user information bit by bit into each frame of the decompressed video stream (bitmap image), and watermarking within the video frame playback time; And a video rendering filter 13 for playing the marked bitmap image.

FIG. 3 is an exemplary diagram illustrating a process of inserting a bit unit of user information into each frame according to the present invention, and illustrates a process of dividing and inserting user information into each frame of a video image. This process is performed inside the watermarking insertion filter 12 as described above.

The watermarking insertion filter 12 extracts and stores user information divided into bits and stores the information, and then inserts the minimum information divided into bits into the respective video frames when the video is played. This is achieved within the playing time of the frame.

As shown in FIG. 3, the watermarking insertion filter 12 converts the RGB color format from the RGB color format into luminance (Y: luminance) and color difference (U, V: chrominance) of the bitmap image decompressed from the video decoder filter 11. (Discrete Cosine Transform) conversion of 8 × 8 block of Y component from (format) information), and select the block in which DC (Direct Current) component falls within a certain range (400 ~ 12000). Insert bit information you want. In this case, the bit representation method calculates an average value M of DC coefficients of both blocks with respect to the selected block, and then uses a difference between the DC coefficient and the average value M of the selected block. That is, when the value of the bit to be expressed in the frame is 0, the difference between the DC value of the selected block and the average value M of both blocks is equal to or less than the offset. When the bit to be expressed is 1, the DC value and M of the selection block are represented. The difference of is expressed by more than offset. The DCT block into which the bit information is inserted is converted into RGB (red, green, blue) bitmap data through a DCT inverse transform process and transmitted to the video renderer filter 13.

FIG. 4 is an exemplary explanatory diagram illustrating a process of configuring user information on a time axis of a video using bit units according to the present invention. FIG. 4 is a video frame in which bit information (watermarked user information) is inserted through a watermarking insertion filter. It is expressed by arranging on the time axis.

As shown in Fig. 4, the bit information (watermarking user information) inserted into the video frame is estimated by a certain number of times (four times) for each bit in anticipation of the loss of the frame on the time axis that may be caused by the capture. It can be seen that it is inserted continuously. This allows for the loss of video frames, depending on the capabilities of the client system being captured when the video capture occurs, so that even if some frame loss occurs, there are extra frames with the same information in addition to the lost frames. This is to enable detection of information.

5 is an exemplary diagram illustrating a process of detecting watermarking information (user information) using the watermarking extraction apparatus (method) according to the present invention.

The watermarking extraction apparatus 20 extracts or stores watermarking information from a distributed video file by capturing or storing a video image in which watermarking information is inserted from a screen. The watermarking extraction device 20 is an independent module (hardware or software module), which detects the bits inserted in each frame from the video being played together with the function of playing the captured video based on DirectShow technology. By reconstructing the user information by combining the information on the time axis, it has a function of showing the information of the user who captured and illegally distributed the video.

As shown in FIG. 5, the watermarking extracting apparatus 20 uses a source filter 21 for reading a file, a decoder filter 22 for releasing a compressed file, and water from decompressed bitmap image frames. It consists of a watermarking detection filter (23) for extracting the marking information, and is used to be compatible with the existing DirectShow-based filters, so that even if the transformation process such as compression by the captured user is developed Using the function provided by the filter, it can be restored to a form that can be detected.

In particular, the watermarking detection filter 23 used in the watermarking extraction apparatus 20 detects bit information of a selected block through DCT transformation of YUV data of each frame by applying the algorithm shown in FIG. As represented in Fig. 4, user information is shown by reconstructing on the time axis of the video image.

In summary, the watermarking extraction apparatus 20 captures a compressed video stream using a source filter 21 for reading the video and a codec suitable for playing the video when the captured or pre-stored distributed video is played back. A video decoder filter 22 for releasing and bit information inserted in each frame of the decompressed video stream (bitmap image) are detected and combined on the time axis to reconstruct user information, thereby capturing or capturing the corresponding video. And a watermarking detection filter 23 showing the stored user's information.

The present invention as described above, by inserting the user information in the video before the user captures the illegal screen, it is possible to detect the user information from the illegally distributed digital video content to impose legal and psychological sanctions on the user who performed illegal capture Watermarking insertion device (hardware or software module) is added to the video player running on the client system used by the user to insert user information into the video in real time, thereby inserting user information. You can naturally distribute the load to each client system and insert user information directly into the video in real time when the video is played, eliminating the need to store different media files on the VOD server.

The method of the present invention as described above may be embodied as a program and stored in a computer-readable recording medium (such as a CD-ROM, a RAM, a ROM, a floppy disk, a hard disk, or a magneto-optical disk). Since this process can be easily implemented by those skilled in the art will not be described in more detail.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

The present invention as described above, despite the use of encryption techniques such as DRM to protect digital content from illegal copying and distribution, screen capture caused by a legitimate user of video content and thereby illegal copying and distribution of the content Due to the copyright infringement, the user information is inserted into the played video in the client system at the time of playing the video, thereby preventing the copyright infringer from being tracked and preventing illegal copying.

In addition, the watermarking insertion device (hardware or software module) of the present invention is composed of a DirectShow-based filter of Microsoft Corporation as an example, and inserted into the existing video player based on DirectShow, so that the separate Instead of creating a separate player to insert user information, it has the effect of upgrading existing video players such as Windows Media Player to a video player that can insert user information. By using web technology, when a user accesses a web site to play a video, it is automatically installed, thereby minimizing user inconvenience and effort.

Claims (16)

delete In the watermarking insertion apparatus on a video player, Video decoding means for releasing a compressed video stream using a codec; Watermarking inserting means for automatically inserting user information bit by bit in each frame of the decompressed video stream (bitmap image) during watermark reproduction to watermark within a video frame reproduction time; And Video rendering means for reproducing the bitmap image of which the user information is watermarked, The watermarking inserting means, It is present between the video decoding means and the video rendering means, the watermarking of the user information is inserted into the DC component of the YUV for the bitmap image received from the video decoding means by bit unit and converted into an RGB bitmap image The watermarking inserting device, which transmits to the video rendering means. The method of claim 2, The watermarking inserting means, Before video capture or storage is performed, it is forcibly executed on the client video player irrespective of the user at the time of playing the video. Device. The method of claim 2, The watermarking inserting means, A watermarking insertion device, automatically installed in a client video player when a user connects to a website to play a video. The method according to claim 3 or 4, The watermarking inserting means, A watermarking insertion device implemented as a DirectShow-based filter and connected to various existing filters in a graph form. The method of claim 5, The client video player, The DirectShow-based filters of Microsoft Corporation are connected and operated in a graph form, and the user information is inserted by a watermarking insertion filter when playing a video. delete In the watermarking extraction device, Image input means for reading a corresponding image when capturing or reproducing a previously stored image; Video decoding means for releasing a compressed video stream using a codec; And Detects bit information inserted in each frame of a decompressed video stream (bitmap image), combines the detected bit information on a time axis, reconstructs user information, and captures or pre-stores the corresponding image. Including watermark detection means for showing, The watermark detection means, Detecting inserted bits of the DC component of the YUV for the bitmap image received from the video decoding means, reconstructing the user information by combining the detected bit information on a time axis, and extracting information of illegally captured user; , Watermarking extraction device. delete In a digital rights management (DRM) system, Watermarking inserting means for automatically inserting user information bit by bit into each frame of the decompressed video stream (bitmap image) during video playback and watermarking within the video frame playback time before video capture or storage is performed; And When playing back a captured or pre-stored distributed image, detecting bit information inserted into each frame of a decompressed video stream (bitmap image), reconstructing the user information by combining the detected bit information on a time axis, Watermarking extraction means for showing the information of the user who captured or pre-stored the image, The watermarking inserting means inserts the user information bitwise into the DC component of the YUV for the bitmap image, And said watermarking detecting means detects the inserted bit information on the DC component of the YUV for the bitmap image and reconstructs the user information by combining the detected bit information on the time axis. 11. The method of claim 10, The watermarking inserting means, It is implemented as a DirectShow-based filter, which is connected to various existing filters in the form of a graph, and is executed on the client video player regardless of the user when the video is played before the video capture or storage is performed. , Digital rights management system. delete delete delete delete delete

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