摘要:
A system and method that detect the location as well as the luminance transition range of slant image edge in a digital image. The variance value for the pixels inside a window in the image is calculated. Based on the variance value, a current pixel can be classified as being in an edge region or in a non-edge region. If the current pixel is in a non-edge region, no further checking is needed, otherwise binary pattern data is generated from the pixels inside the window. Then it is determined whether the current pixel is a center pixel in a luminance transition range of a slant edge based on the binary pattern data at the current pixel location and its neighboring binary pattern data. It is determined if the current pixel is the center pixel in a luminance transition range of a e.g. ±45° direction edge. If it is, then no further processing is needed at the current pixel location and the luminance transition range is considered as 3 pixels wide. Otherwise, based on the neighboring binary pattern data, another checking process is performed to determine whether the current pixel is a center pixel in a luminance transition range other than a ±45° slant edge. If the current pixel is considered as a center pixel in a luminance transition range other than a ±45° slant edge, then the length of the luminance transition range of the slant edge is determined by checking more binary pattern data inside the window.
摘要:
A filtering method and filtering system is applied to an edge orientation map obtained from an edge direction detection system in order to keep accurate edge directions and filter out false edges or edges with wrong directions. If an edge direction does not have a certain minimum length, then that direction is filtered out and a default direction is provided. Additional assurances can be obtained by insuring that the edge direction has a certain minimum width. If an edge direction does not have the minimum width, then that edge direction is filtered out and the default direction is provided. A direction smoother can be applied to the directions in the edge orientation map to smooth the changing of neighboring edge directions. This process is found to be effective in improving the visual quality of an image that is interpolated based on edge directions.
摘要:
This disclosure describes techniques for coding transform coefficients for a block of video data. According to some aspects of this disclosure, a coder (e.g., an encoder or decoder) may map between a code number cn and level_ID and run values associated with a first transform coefficient of the block of video data according to a first technique (e.g., a structured mapping), and map between a code number cn and level_ID and run values associated with a second coefficient of the block using a second technique. According to other aspects of this disclosure, the coder may map between a code number cn and level_ID and run syntax elements using different mathematical relationships, depending on a determined value of the code number cn or the level_ID syntax element. For example, the coder may access a mapping table of a plurality of mapping tables differently, dependent on the determined value.
摘要:
A computing device determines whether a prediction unit (PU) in a B slice is restricted to uni-directional inter prediction. In addition, the computing device generates a merge candidate list for the PU and determines a selected merge candidate in the merge candidate list. If the PU is restricted to uni-directional inter prediction, the computing device generates a predictive video block for the PU based on no more than one reference block associated with motion information specified by the selected merge candidate. If the PU is not restricted to uni-directional inter prediction, the computing device generates the predictive video block for the PU based on one or more reference blocks associated with the motion information specified by the selected merge candidate.
摘要:
An improved system and method for providing improved inter-layer prediction for extended spatial scalability in video coding, as well as improving inter-layer prediction for motion vectors in the case of extended spatial scalability. In various embodiments, for the prediction of macroblock mode, the actual reference frame index and motion vectors from the base layer are used in determining if two blocks should be merged. Additionally, multiple representative pixels in a 4×4 block can be used to represent each 4×4 block in a virtual base layer macroblock. The partition and motion vector information for the relevant block in the virtual base layer macroblock can be derived from all of the partition information and motion vectors of those 4×4 blocks.
摘要:
For a block of video data, a video encoder can signal to a video decoder, using a context-based adaptive binary arithmetic coding (CABAC) process, a selected intra-prediction mode using a codeword that is mapped to a modified intra-prediction mode index. The video decoder can perform a context-based adaptive binary arithmetic coding (CABAC) process to determine the codeword signaled by the video encoder, determine the modified intra-prediction mode index corresponding to the codeword, determine most probable modes based on a context, map the modified intra-prediction mode index to an intra-prediction mode index by comparing the modified intra-prediction mode index to the mode indexes of the most probable modes, and determine the selected intra-prediction mode used to encode the block of video data based on the intra-prediction mode index.
摘要:
A video encoder can maintain, by generating, storing, adjusting, altering, and/or updating, one or more variable length coding (VLC) tables that represent a mapping of prediction modes to codewords. One or more codewords representing a selected prediction mode can be communicated to the decoder for a CU of a frame. The decoder maintains one or more VLC tables that match the VLC tables maintained by the video encoder. Thus, based on the one or more codewords received from the video encoder, the video decoder can determine the prediction mode used to encode a CU.
摘要:
A computing device determines whether a prediction unit (PU) in a B slice is restricted to uni-directional inter prediction. In addition, the computing device generates a merge candidate list for the PU and determines a selected merge candidate in the merge candidate list. If the PU is restricted to uni-directional inter prediction, the computing device generates a predictive video block for the PU based on no more than one reference block associated with motion information specified by the selected merge candidate. If the PU is not restricted to uni-directional inter prediction, the computing device generates the predictive video block for the PU based on one or more reference blocks associated with the motion information specified by the selected merge candidate.
摘要:
In an example, aspects of this disclosure relate to a method for decoding transform coefficients in a video decoding process that includes decoding a one-dimensional array of transform coefficients, and performing a scan on the one-dimensional array of transform coefficients according to a sub-block scan order and a coefficient scan order to produce a block of transform coefficients, where the sub-block scan order comprises an order in which each sub-block of a plurality of sub-blocks within the block is scanned, and where the coefficient scan order comprises an order in which the transform coefficients corresponding to each sub-block of the plurality of sub-blocks are scanned.
摘要:
In an example, aspects of this disclosure relate to a method of coding video data that generally includes determining prediction information for a block of video data, where the block is included in a coded unit of video data and positioned below a top row of above-neighboring blocks in the coded unit, and where the prediction information for the block is based on prediction information from one or more other blocks in the coded unit but not based on prediction information from any of the top row of blocks in the coded unit. The method also generally includes coding the block based on the determined prediction information.