Abstract: A preprocessing mechanism automatically processes a video sequence in order to obtain a set of views suitable for structure from motion (SaM) processing. The preprocessor employs a frame decimation algorithm which removes redundant frames within the video sequence based on motion estimation between frames and a sharpness measure. The motion estimation can be performed either globally or locally. The preprocessor can be configured to process static video sequences (i.e., previously acquired/captured) to select a minimal subsequence of sharp views form the video sequence, or to process the frames of a video sequence as they are being captured to discard frames which are redundant. In either configuration, the goal of the preprocessor is to select a minimal sequence of sharp views tailored for SaM processing.

Abstract: In a method of video data compression a video frame in a sequence of frames is divided into a number of macroblocks, a particular macroblock being adjacent to a number of previously coded macroblocks including both intra-coded and inter-coded macroblocks. The method includes selecting either a full prediction or limited prediction type in encoding the particular macroblock to provide a corresponding data bit stream, full prediction using both adjacent inter-coded and intra-coded macroblocks, and limited prediction using intra-coded macroblocks only. A signal is provided along with the bit stream to indicate the selected prediction type to a decoder disposed to recover data from the bit stream. The prediction type may be either signaled explicitly, such as by providing a code word in the bit stream, or may be inferred implicitly by selected values or levels of a coding variable.

Abstract: In a method for transmitting a multimedia presentation comprising a number of media objects: the media objects are organized in a multimedia container or container format; identifiers referring to the media objects are organized in the same container; and an identifiable file coordinating the media objects is also provided in the container.

Abstract: A method and apparatus for maximizing the prediction utility of previously encoded macroblocks by adjusting the scanning order of the blocks within a macroblock to be encoded is disclosed. Where no previously encoded blocks are available above the macroblock being encoded, the alternative scanning orders allow for maximum utility of previously encoded blocks located to the left of the macroblock being encoded. Where no previously encoded blocks are available either above or to the left of the macroblock being encoded, the alternative scanning orders allow for maximum utility of information from blocks that are presently being encoded in the same macroblock. The particular scanning order used may be signaled implicitly based on the location of the macroblock being encoded, or it may be signaled explicitly by code words within the bitstream containing the encoded block information.

Abstract: A system and a method for coding and decoding video data are invented. In a system and method of video data compression a video frame is divided into a sequence of image blocks, wherein one of several possible block-coding modes is an implicit global motion compensation (IGMC) mode, which is used to copy pixels from a previous frame displaced by a predicted motion vector. In another embodiment of the invention, a system and method of a video data compression, a video frame is segmented into a sequence of slices, wherein each slice includes a number of macroblocks. Respective slices are encoded and a signal is included in the header of an encoded slice to indicate whether the slice is GMC enabled, that is, whether global motion compensation is to be used in reconstructing the encoded slice. If so, GMC information, such as information representing a set of motion vectors, is included with the slice.

Abstract: The present invention is directed to providing a method and apparatus for efficiently compressing and reconstructing a header of a real time communication packet. In a header compressor, a header field value is applied to a modulo X operator which can, for example, divide the header field value by a value X, and output the remainder. Optionally, a checksum may be appended to the remainder. The header field value may be scaled prior to being applied to the modulo X operator. The compressed header field which is output from the header compressor includes the remainder with or without the checksum appended. A header decompressor includes a field reconstructor which reconstructs the received compressed header field in response to the remainder value and range information. The range information represents a range of possible field values which can be reconstructed from the received remainder value.

Abstract: In a method of video data compression a video frame in a sequence of frames is divided into a number of macroblocks, a particular macroblock being adjacent to a number of previously coded macroblocks including both intra-coded and inter-coded macroblocks. The method includes selecting either a full prediction or limited prediction type in encoding the particular macroblock to provide a corresponding data bit stream, full prediction using both adjacent inter-coded and intra-coded macroblocks, and limited prediction using intra-coded macroblocks only. A signal is provided along with the bit stream to indicate the selected prediction type to a decoder disposed to recover data from the bit stream. The prediction type may be either signaled explicitly, such as by providing a code word in the bit stream, or may be inferred implicitly by selected values or levels of a coding variable.

Abstract: In a method and a device for coding binary matrices, in particular sparse binary matrices, a matrix is gradually partitioned into sub-matrices During the gradual partitioning the number of binary ones are counted for each resulting sub-matrix. If a resulting sub-matrix does not consist of mixed symbols no further partitioning of that sub-matrix is required. The counted number of binary ones for each sub-matrix is then coded and transmitted. The method provides an efficient coding particularly for sparse binary matrices such as bi-level images or bit maps.

Abstract: In a method and a device for transforming a stream of digital numbers, the correlation between successive numbers is utilized in order to obtain a new stream having a very low correlation between the numbers, whereby the sequence of numbers can be coded much more efficiently from a compression point of view. The numbers are for this purpose coded with the difference between a predicted number (s′(i)) and the actual number (s(i)) taking into account that the sequence does not need to be possible to decode in reverse order. The non-reversible codes can also be applied in lossy data compression schemes. Such schemes can change in accordance with the currently available bandwidth in order to obtain a graceful degradation and optimal bandwidth usage when the compressed data stream is transmitted over a channel having a time varying bandwidth. A general method and device for reversible coding are also provided.

Abstract: A preprocessing mechanism automatically processes a video sequence in order to obtain a set of views suitable for structure from motion (SaM) processing. The preprocessor employs a frame decimation algorithm which removes redundant frames within the video sequence based on motion estimation between frames and a sharpness measure. The motion estimation can be performed either globally or locally. The preprocessor can be configured to process static video sequences (i.e., previously acquired/captured) to select a minimal subsequence of sharp views form the video sequence, or to process the frames of a video sequence as they are being captured to discard frames which are redundant. In either configuration, the goal of the preprocessor is to select a minimal sequence of sharp views tailored for SaM processing.

Abstract: In a method and an apparatus for mixing video streams, the video mixing takes place in the compressed domain. The computational load is thereby reduced, which in turn saves costs. A Possible application is a multi-point control unit (MCU) provided as a centralized unit in a video conference.

Abstract: The present invention relates to a protection device for detecting at least one faulty phase in an electrical network. The device comprises a band exclusion filter for each phase for filtering away the signals which have the same frequency as the nominal frequency of the network, amplifiers, rectifiers and peak value forming means for each phase. In addition, the different phase signals are fed to a function element which delivers a signal to a level and comparison device for each phase, where the signal is compared with the signals in the respective phase.