Patent application number | Description | Published |
20090052535 | SYSTEM AND METHOD FOR PROVIDING IMPROVED INTRA-PREDICTION IN VIDEO CODING - A system and method for improving the efficiency of decoding intra-coded blocks in video decoding, even in the event that neighboring pixels of the block are unavailable. According to various embodiments, in addition to information that is used to describe how a prediction is formed using a specified process, other “side” information is also transmitted for use in the decoding process. For example, after the intra-prediction direction of a block is decoded, it is determined whether the intra-prediction requires pixels that are unavailable for the block. If such pixels are needed, than side information may be parsed from the bitstream in a predetermined manner. The prediction signal may then be reconstructed for the block using various pieces of information. | 02-26-2009 |
20100195923 | IMPLEMENTATION OF A TRANSFORM AND OF A SUBSEQUENT QUANTIZATION - An approximation of a DCT and a quantization are to be applied subsequently to digital data for compression of this digital data. In order to improve the transform, a predetermined transform matrix is simplified to require less operations when applied to digital data. In addition, elements of the simplified transform matrix constituting irrational numbers are approximated by rational numbers. These measures are compensated by extending a predetermined quantization to include the operations which were removed in the simplification of the predetermined transform matrix. The included operations are further adjusted to compensate for the approximation of elements of the simplified transform matrix by rational numbers. If the simplified transform matrix and the extended quantization are used as basis for implementation, a fast transform with a good resulting quality can be achieved. An approximation of an IDCT employed in decompression of compressed digital data can be simplified correspondingly. | 08-05-2010 |
20120189057 | Motion Prediction in Video Coding - There is disclosed apparatuses, methods and computer programs for utilizing motion prediction in video coding. Coding type of a block of pixels of a video representation encoded in a bitstream is read, where values of said pixels having a first precision. If the type of the block is a block predicted by using two or more reference blocks, a first reference pixel location in a first reference block is determined and a second reference pixel location in a second reference block is determined. The first reference pixel location is used to obtain a first prediction having a second precision, which is higher than the first precision. The second reference pixel location is used to obtain a second prediction, also having the second precision. The first prediction and the second prediction are combined to obtain a combined prediction having the first precision. | 07-26-2012 |
Patent application number | Description | Published |
20090016626 | JOINT CODING OF MULTIPLE TRANSFORM BLOCKS WITH REDUCED NUMBER OF COEFFICIENTS - A system and method for video/image encoding and decoding, where transform coefficients associated with a plurality of blocks are reorganized and coded together. Various embodiments perform transform and quantization and generate transform coefficients, where the coefficients of the transform blocks are reorganized and interleaved. Additionally, an encoding process involves coding only a subset of the transform coefficients belonging to the transform blocks resulting in one or more transform blocks less than the original number of transform blocks, and putting this into a bitstream. A decoding process involves decoding the one or more resulting transform blocks including the subset of transform coefficients from the bistream, the transform coefficients being put in an array and decoded. The decoder de-interleaves the decoded transform coefficients and any remaining coefficients of the one or more transform blocks are filled in according to a plurality of different methods. After the one or more transform blocks are fully decoded, inverse transform and inverse quantization are performed and residual data is generated. | 01-15-2009 |
20090097545 | Fixed-Point Implementation of an Adaptive Image Filter with High Coding Efficiency - In accordance with an embodiment of the present invention, a method comprising: representing coefficients of an adaptive image filter in binary words wherein the coefficients are restricted and the binary words have a maximum number of bits defined at least in part by a precision index; computing at least one of a convolution sum and multiple partial convolution sums of the adaptive image filter wherein the at least one of a convolution sum and multiple partial convolution sums having a constrained value range and having a binary representation with a fixed maximum number of bits; and generating the output of the adaptive image filter based at least in part on the at least one of a convolution sum and multiple partial convolution sums, is disclosed. | 04-16-2009 |
20090097547 | Fixed-Point Implementation of an Adaptive Image Filter with High Coding Efficiency - In accordance with an embodiment of the present invention, a method comprising: representing coefficients of an adaptive image filter in binary words wherein the coefficients are restricted and the binary words have a maximum number of bits defined at least in part by a precision index; computing at least one of a convolution sum and multiple partial convolution sums of the adaptive image filter wherein the at least one of a convolution sum and multiple partial convolution sums having a constrained value range and having a binary representation with a fixed maximum number of bits; and generating the output of the adaptive image filter based at least in part on the at least one of a convolution sum and multiple partial convolution sums, is disclosed. | 04-16-2009 |
20090304084 | COMBINED MOTION VECTOR AND REFERENCE INDEX PREDICTION FOR VIDEO CODING - A system and method for improving the coding efficiency of motion vector information in video coding. According to various embodiments, a list of motion vector predictor candidates is arranged according to predefined rules. Each motion vector also has a reference index associated with it. One of the motion vector candidates is then selected as a predictor based on predefined rules, or the selection is explicitly signaled in the bitstream. The reference index associated with the selected motion vector is used as a reference index for the current block. The reference index is predicted along with the motion vector. Such embodiments can improve the compression efficiency of modern video codecs. | 12-10-2009 |
20100150226 | SWITCHING BETWEEN DCT COEFFICIENT CODING MODES - A system and method is provided for improving efficiency when entropy coding a block of quantized transform coefficients in video coding. Quantized coefficients are coded in two separate coding modes, namely, a run mode to a level mode coding mode. “Rules” for switching between these two modes are provided, and various embodiments are realized by allowing an entropy coder to adaptively decide when to switch between the two coding modes based on context information, the rules and/or by explicitly signaling the position of switching (e.g., whether or not it should switch coding modes). | 06-17-2010 |
20100246692 | FLEXIBLE INTERPOLATION FILTER STRUCTURES FOR VIDEO CODING - Systems and methods of signaling different filter structures for each pixel or sub-pixel position in motion compensation prediction video coding are provided. An encoder signals to a decoder one filter structure among a plurality of pre-defined candidates that is used for a respective pixel or sub-pixel position. In accordance with one embodiment, filter structures signaled to the decoder from the encoder “switch” between directional filter and radial filter structures during interpolation at the sub-pixel level. In accordance with another embodiment, filter structures that are signaled may switch between a directional filter structure and a separable filter structure at the sub-pixel level. Thus, not only can an encoder switch between different filter structures during interpolation, but a filter structure pair is provided that the encoder can utilize to interpolate a wide range of signals without increasing tap-length. | 09-30-2010 |
20100295712 | METHOD FOR CODING AND AN APPARATUS - The disclosure relates to variable length encoding and decoding. A symbol is variable length encoded by selecting a variable length code word table from a set of variable length code word tables based on a value of a variable; selecting a code word from the selected variable length code word table on the basis of said symbol; and updating the value of said variable by comparing the correspondence between said symbol and said variable. If the comparison indicates that the value of the variable is smaller than the symbol, the value of said variable is incremented; else if the comparison indicates that the value of the variable is greater than the symbol, the value of said variable is decremented; else the value of the variable is not amended. | 11-25-2010 |
20120169519 | METHOD FOR CODING AND AN APPARATUS - A method comprising receiving a syntax element to be encoded as a code word of a set of code words, determining a mapping between the syntax element and the code word on the basis of a hierarchy level in a tree structure, using the mapping to obtain the code word, and updating the mapping is disclosed. | 07-05-2012 |
20120250763 | METHOD AND APPARATUS FOR PROVIDING COMPLEXITY BALANCED ENTROPY CODING - A method, apparatus and computer program product are provided to enable the provision of efficient processing in the area of video coding and decoding by employing complexity balanced entropy coding in order to provide a high level of capability with respect to video coding and decoding in a cost effective manner. A method includes categorizing a plurality of syntax elements of video content into first and second categories based on a frequency of occurrence of the syntax elements in the video content. The method also entropy codes symbols that correspond to the first category of syntax elements and that have been subjected to a context update. Further, the method entropy codes symbols that correspond to the second category of syntax elements and that have bypassed context updating. A corresponding apparatus and computer program product are also provided. | 10-04-2012 |