Abstract: An AV stream processing system includes an AV stream input unit which receives an AV stream having an AV content information field including first copy control information, and an AV content field including second copy control information, a determination unit which extracts the first and second copy control information from the received AV stream and determines whether the first copy control information has been modified, and an AV stream decryption unit which processes the received AV stream according to predetermined criteria, when the first copy control information has been modified.

Abstract: A method of constructing a unique domain for preventing content from being illegally used by an unauthorized third person in a public key-based architecture and applying the constructed domain to a home network using universal plug and play (UPnP). The method of the present invention includes selecting one of controlled devices that are operable as a master device and determining the selected device as the master device; performing device authentication in such a manner that other controlled devices receive a secret information block from the determined master device and create certificates; and determining slave devices by selecting one or more devices among the authenticated controlled devices.

Abstract: An apparatus and method to encrypt data having hierarchical information are provided. The apparatus includes an N-th layer key generator, which generates an N-th layer key, an (N+1)-th layer key generator, which generates an (N+1)-th layer key by applying the N-th layer key to a predetermined function, an N-th layer data encryptor, which encrypts N-th layer data using the N-th layer key, and an (N+1)-th layer data encryptor, which encrypts (N+1)-th layer data using the (N+1)-th layer key.

Abstract: An object activity modeling method which can efficiently model complex objects such as a human body is provided. The object activity modeling method includes the steps of (a) obtaining an optical flow vector from a video sequence; (b) obtaining the probability distribution of the feature vector for a plurality of video frames, using the optical flow vector; (c) modeling states, using the probability distribution of the feature vector; and (d) expressing the activity of the object in the video sequence based on state transition. According to the modeling method, in video indexing and recognition field, complex activities such as human activities can be efficiently modeled and recognized without segmenting objects.

Abstract: Managing metadata in a metadata transmission server by generating a plurality of metadata fragment data by partitioning metadata to be transmitted based upon predetermined segment units, selecting predetermined metadata fragment data from among the plurality of the metadata fragment data, generating metadata-related authentication information using the selected metadata fragment data, and transmitting the selected metadata fragment data and the metadata-related authentication information including data format information indicating type of the selected metadata fragment data. A metadata receiving client uses the transmitted metadata fragment data, the metadata-related authentication information and the metadata format type information to authenticate the received metadata.

Abstract: A method for describing pattern repetitiveness which may exist within an image, is provided. The method of describing pattern repetitiveness of an image comprises: (a) projecting an image on a predetermined axis having a predetermined direction, (b) decomposing the projected image down one level, (c) increasing a threshold value while a pattern quantizing value is retained, and denoising the decomposed data, and (d) describing pattern repetitiveness of the image using the pattern quantizing value of the denoised data and the threshold value used for denoising. Because the method of describing pattern repetitiveness of an image effectively denoises the original image without damaging the pattern repetitiveness of the original image, and the pattern repetitiveness is described using the denoised data, it is possible to describe more definite pattern repetitiveness.

Abstract: Provided is a contents sharing method between a mobile terminal and a local server. The contents sharing method between a client terminal storing metadata and a server terminal storing the metadata, the method comprising requesting the server terminal for a contents share service; and receiving information on contents corresponding to matching metadata as a result of comparing the metadata stored in the, client terminal and the metadata stored in the server terminal, thereby sharing contents desired by the user without the user's intervention. Also, the user can communicate desired contents information with people in a bus, subway, library, etc., which forms a social network, and produces a contents flow between mobile terminals, thereby creating a new business model such as contents resale, promotion, etc.

Abstract: An object activity modeling method which can efficiently model complex objects such as a human body is provided. The object activity modeling method includes the steps of (a) obtaining an optical flow vector from a video sequence; (b) obtaining the probability distribution of the feature vector for a plurality of video frames, using the optical flow vector; (c) modeling states, using the probability distribution of the feature vector; and (d) expressing the activity of the object in the video sequence based on state transition. According to the modeling method, in video indexing and recognition field, complex activities such as human activities can be efficiently modeled and recognized without segmenting objects.

Abstract: A color image processing method is provided. The color image processing method includes the step of: (a) indexing a color image by assigning representative colors of an image to a color space divided into a plurality of regions. The color image processing method may be applied to object-based image processing such as MPEG-7, and fast search and retrieval of multimedia content can be made.

Abstract: A color image processing method is provided. The color image processing method includes the step of: (a) indexing a color image by assigning representative colors of an image to a color space divided into a plurality of regions. The color image processing method may be applied to object-based image processing such as MPEG-7, and fast search and retrieval of multimedia content can be made.

Abstract: A method for retrieving an image texture descriptor for describing texture features of an image, including the steps of (a) filtering input images using predetermined filters having different orientation coefficients, (b) projecting the filtered images onto axes of each predetermined direction to obtain data groups consisting of averages of each directional pixel values, (c) selecting candidate data groups among the data groups by a predetermined classification method, (d) determining a plurality of indicators based on orientation coefficients of the filters used in filtering the candidate data groups, and (e) determining the plurality of indicators as the texture descriptor of the image. The texture descriptors which allow kinds of texture structure present in an image to be perceptually captured can be retrieved.

Abstract: An image retrieval method and apparatus independent of an illumination change are provided. The image retrieval method involves: inputting a query image; detecting an illumination color from the query image and converting the illumination color into a standard illumination color; extracting color information of the query image by using color descriptors; and retrieving a similar image by comparing the extracted color information with color information of a database which converts a variety of images into images of standard illumination colors and extracts and stores the color information of the images in advance. According to the method, without changing the structures of color descriptors or a similarity comparison using color information, an image retrieval independent of illumination changes is enabled by adding only a preceding step of standard illumination conversion.

Abstract: An image retrieval method and apparatus independent of an illumination change are provided. The image retrieval method involves: inputting a query image; detecting an illumination color from the query image and converting the illumination color into a standard illumination color; extracting color information of the query image by using color descriptors; and retrieving a similar image by comparing the extracted color information with color information of a database which converts a variety of images into images of standard illumination colors and extracts and stores the color information of the images in advance. According to the method, without changing the structures of color descriptors or a similarity comparison using color information, an image retrieval independent of illumination changes is enabled by adding only a preceding step of standard illumination conversion.

Abstract: A digital rights management (DRM) conversion method and apparatus are provided. The DRM conversion method includes: (a) obtaining a first content key for the first content and a second content key for the second content through reciprocal authentication between a DRM conversion apparatus and a DRM conversion server, the DRM conversion apparatus converting the first content into the second content; and (b) converting the first content into the second content wherein the DRM conversion apparatus is disconnected from the DRM conversion server. Accordingly, it is possible to transmit content between devices using different DRM systems even offline with the use of a conversion manager (CM) that performs authentication and DRM conversion operations.

Abstract: A method for retrieving an image texture descriptor for describing texture features of an image, including the steps of (a) filtering input images using predetermined filters having different orientation coefficients, (b) projecting the filtered images onto axes of each predetermined direction to obtain data groups consisting of averages of each directional pixel values, (c) selecting candidate data groups among the data groups by a predetermined classification method, (d) determining a plurality of indicators based on orientation coefficients of the filters used in filtering the candidate data groups, and (e) determining the plurality of indicators as the texture descriptor of the image. The texture descriptors which allow kinds of texture structure present in an image to be perceptually captured can be retrieved.

Abstract: A method for extracting from an image a shape descriptor which describes shape features of the image is provided. The shape descriptor extracting method includes: (a) extracting a skeleton from an input image, (b) obtaining a list of straight lines by connecting pixels based on the extracted skeleton, and (c) determining the regularized list of straight lines obtained by normalizing a list of straight lines as the shape descriptor. A shape descriptor extracted according to the shape descriptor extracting method possesses information of a schematic feature of a shape included in an image. Therefore, the shape descriptor extracting method effectively extracts a local motion in the data collection of the same category, and the number of extracted shapes is not limited to the number of objects.

Abstract: Provided are a system and a method for transmitting and receiving contents at home. The content service method includes: reconstructing encrypted compressed contents back into compressed contents by decrypting the encrypted compressed contents according to a first scheme; encrypting the reconstructed compressed contents according to a second scheme; and transmitting the encrypted compressed contents via a predetermined link. Therefore, the encrypting and decrypting of contents are easily supported without an encoding process in a content server terminal at home.

Abstract: A digital video processing method and an apparatus thereof are provided. The method for processing digital images received in the form of compressed video streams comprising the step of determining a region intensity histogram (RIH) based on information on motion compensation of inter frames. The RIH information is obtained based on the motion compensation values of inter frames, and the RIH information is a good indicator of motion information of a video scene. Also, since the RIH information is quite a good indicator of intensity of the video scene, video streams having similar intensities can be effectively searched by searching for similar video scenes based on the RIH information obtained by the digital video processing method.

Abstract: A method of transmitting copy control information in a video data transmitting/receiving system is provided. The method includes: decoding compressed contents into prior-to-compression contents; generating packets including the decoded contents and the copy control information; and transmitting the packets through a predetermined link. An unauthorized copying of the decoded video data is prevented.

Abstract: Provided is a method of transmitting content processed according to first digital rights management (DRM) to a device that uses second DRM. The method includes generating a ticket using a first license server and a second license server, the first license server issuing a first license for use in the first DRM and the second license server issuing a second license for use in the second DRM; the second device obtaining a second content key required to process the content using the ticket and the second DRM; and the second device receiving the content from the first device and processing the content using the second content key and the second DRM. The ticket includes use control information that specifies a restriction of use of the content, and the second content key required to process the content using the second DRM.