| Patent application number | Description | Published |
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| 20080247467 | Adaptive interpolation filters for video coding - In digital video image encoding and decoding, a filter type is selected based on symmetrical properties of the images and coefficient values of an interpolation filter are calculated based on the selected filter type. Coefficient values, filter tap-length and selected filter-type are provided in the encoded video data. Coefficient values are also calculated based on a prediction signal representative of the different between a video frame and a reference image. The prediction signal is calculated from the reference image based on a predefined base filter and motion estimation performed on the video frame. The predefined base filter has fixed coefficient values. Coefficient values are selected from interpolation of pixel values in a selected image segment in the video frame. Symmetry properties of images can be a vertical symmetry, a horizontal symmetry and a combination thereof, so that only a portion of the filter coefficients are coded. | 10-09-2008 |
| 20080253459 | HIGH ACCURACY MOTION VECTORS FOR VIDEO CODING WITH LOW ENCODER AND DECODER COMPLEXITY - Two-stage interpolation can be provided for frame prediction samples with quarter-pixel and finer accuracy. All samples of quarter-pixel and finer accuracy can use either half or full/integer-pixels in a bi-linear interpolation to allow for the use of higher accuracy motion vectors, such as one-eighth-pixel accuracy motion vectors. The motion vectors can be restricted in a manner such that they are not allowed to point to every possible sub-pixel sample on a sub-pixel grid, but rather a subset of those sub-pixel samples. In addition, the same full/integer and half-pixel samples that can be used to obtain a quarter-pixel sample can also be used to obtain a one-eighth-pixel sample that the quarter-pixel sample is connected to. Hence, for every quarter-pixel sample, a motion vector could point to two additional positions/locations with one-eighth-pixel accuracy, where the two additional positions/locations can be calculated using the same half or integer-pixel samples which were used to obtain the quarter-pixel sample. Therefore, an arbitrary motion vector accuracy can be achieved without the need to perform additional interpolation stages or increase the complexity of a decoder configured to decode motion vector data. | 10-16-2008 |
| 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 |
| 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 |
| 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 |
| 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 |
| 20100296587 | VIDEO CODING WITH PIXEL-ALIGNED DIRECTIONAL ADAPTIVE INTERPOLATION FILTERS - A system and method for implementing an adaptive interpolation filter structure that achieves high coding efficiency with significantly less complexity than more conventional systems. In various embodiments, a set-of integer pixels are defined that are used in the interpolation process to obtain each sub-pixel sample at different locations. Samples at each sub-pixel positions are generated with independent pixel-aligned one-dimensional (1D) adaptive interpolation filters. The filter coefficients are be transmitted to a decoder or stored into a bit stream. At the decoder end, the received filtered coefficients may be used in an interpolation process to create a motion-compensated prediction. | 11-25-2010 |
