Patent application number | Description | Published |
20110274158 | Method and Apparatus of Adaptive Loop Filtering - In a block-based motion compensated system, coding noises may arise due to lossy operations such as quantization. Deblocking is often used to alleviate visibility of coding artifacts by applying filtering across block boundaries adaptively. In the recent HEVC development, adaptive loop filtering (ALF) is being adopted to process deblocked reconstruction frames. Adaptive loop filtering is applied to reconstructed video data across multiple frames to reduce visibility of coding artifacts in the temporal domain. In a HEVC system, conventional ALF can be selectively turned ON or OFF for each block in a frame or a slice. The advanced ALF disclosed here allows a choice of multiple filter sets that can be applied to the reconstructed video data adaptively. Furthermore, the advanced ALF adopts a new unit for the filtering process to apply so that more flexible and/or localized processing can be provided. Furthermore, the advanced ALF allows a decoder to derive respective information for applying the filtering process without side information. | 11-10-2011 |
20120008688 | Method and Apparatus of Temporal Motion Vector Prediction - An apparatus and method for motion vector prediction for a current block in a picture are disclosed. In video coding systems, the spatial and temporal redundancy is exploited using spatial and temporal prediction to reduce the information to be transmitted. Motion Vector Prediction (MVP) has been used to further conserve the bitrate associated with motion vector. In conventional temporal MVP, the predictor is often based on a single candidate such as the co-located motion vector in the previous frame/picture. If the co-located motion vector in the previous frame/picture does not exist, the predictor for the current block is not available. A technique for improved MVP is disclosed where the MVP utilized multiple candidates based on co-located motion vectors from future and/or past reference pictures. The candidates are arranged according to priority order to provide better availability of MVP and also to provide more accurate prediction. Furthermore, the MVP technique disclosed can be operated in a closed-loop fashion so that no additional side information or minimum additional side information is required. | 01-12-2012 |
20120082241 | Method and Apparatus of Adaptive Loop Filtering - A method and apparatus for processing in-loop reconstructed video using an in-loop filter is disclosed. In the recent HEVC development, adaptive loop filtering (ALF) is being adopted to process in-loop reconstruction video data, where ALF can be selectively turned ON or OFF for each block in a frame or a slice. An advanced ALF is disclosed later that allows a choice of multiple filter sets that can be applied to the reconstructed video data adaptively. In the present disclosure, pixels of the in-loop reconstructed video data are divided into a plurality of to-be-filtered regions, and an in-loop filter from a filter set is determined for each to-be-filtered region based on a rate-distortion optimization procedure. According to one embodiment of the present invention, computation of cost function associated with the rate-distortion optimization procedure is related to correlation values associated with original video data and the in-loop reconstructed video data. Furthermore, the correlation values can be shared by the multiple candidate filters during the rate-distortion optimization procedure for said each to-be-filtered region. In another embodiment, the correlation values can be shared by multiple candidate to-be-filtered regions of an area of the in-loop reconstructed video data during the rate-distortion optimization procedure for the area of the in-loop reconstructed video data. | 04-05-2012 |
20120082244 | Method and Apparatus of Region-Based Adaptive Loop Filtering - In a block-based motion compensated system, coding noises may arise due to lossy operations. Adaptive loop filter (ALF) is a technique used to improve the quality. A pixel adaptive (PA) ALF method was developed that uses the Sum-modified Laplacian Measure (SLM) to classify pixels and applies a respective ALF filter to each pixel according to the SLM. While the PA ALF achieves better performance over a conventional single filter (SF) based ALF, the PA ALF causes higher complexity and consumes more power due to the high complexity and per-pixel filter switching. Accordingly region based ALF scheme is disclosed which allows adaptive filter selection on a region by region basis and does not require per-pixel filter switching. In one embodiment according to the present invention, a picture is divided into M×N regions. The region based ALF also allows region merging for the M×N regions to improve performance. In another aspect of the present invention, the optimal ALF design also takes into consideration of the system complexity by using rate-distortion-complexity optimization (RDCO). The RDCO technique is also applied to sample adaptive offset (SAO) design. | 04-05-2012 |
20120106622 | Method and Apparatus of Slice Grouping for High Efficiency Video Coding - In the H.264/AVC standard, one of the new characteristics is the possibility of dividing an image in regions called slice groups. The use of slice groups provides various possible advantages such as prioritized transmission, error resilient transmission, and etc. The slice groups can be formed by flexible macroblock ordering (FMO), where each picture can be divided into slice groups in different scan patterns of the macroblocks. In the high efficiency video coding (HEVC) under development, a more flexible block structure, called coding unit (CU), is used as the unit to process video data. The picture is first divided into largest CUs (LCUs) and each LCU is adaptively split into smaller CUs using a quadtree until leaf CUs are reached. In the current HEVC development, there is neither slice nor slice group structure being considered. The LCU size used for HEVC is 16 times as large as the macroblock size used in the H.264/AVC standard. Therefore, it is very desirable to develop slice and slice group structure suited for HEVC to offer various benefits of error resilience, parallel processing, reduced line (row) buffer requirement, and etc. Accordingly, slice group types including raster scan type, vertical stripe type, regions of interest type and full flexibility type are developed for HEVC. Furthermore, various syntax elements are incorporated in the sequence header or the picture header to convey information associated with the slice group structure. | 05-03-2012 |
20120106652 | Apparatus and Method for High Efficiency Video Coding Using Flexible Slice Structure - An apparatus and method for video coding based on flexible slice structure are disclosed. In the recent high efficiency video coding (HEVC) development, the slice may contain multiple LCUs instead of macroblocks. The LCU size being considered is 64×64 pixels which is much larger than the macroblock size of 16×16 pixels. Compared with the macroblock aligned slice for H.264, the LCU-aligned slice for HEVC does not provide enough granularities for dividing video frames. Consequently, a flexible slice structure is developed where slice partition is based on smaller coding units. In the flexible slice structure, the first LCU and the last LCU of the slice are allowed to be a fractional LCU, which is derived from a whole LCU using quadtree partition. Syntax elements are also developed to enable conveyance of flexible slice structure between an encoder and a decoder efficiently. | 05-03-2012 |
20120114034 | Method and Apparatus of Delta Quantization Parameter Processing for High Efficiency Video Coding - In the current high efficiency video coding development, each LCU has its own quantization parameter (QP) and the difference between a current QP and a reference QP is transmitted instead of the QP value itself. Since the LCU is much larger than the macroblock of AVC/H.264, using one delta QP per LCU may cause rate control unable to adapt to the bitrate quickly enough. Consequently there is a need to adopt delta QP in units smaller than LCU to provide more granular rate control. Furthermore, it is desirable to develop a system that is capable of facilitating more flexible delta QP. Accordingly, adaptive quantization parameter processing is disclosed where a QP minimum CU size for incorporating or deriving a delta QP is indicated selectively in the slice level or in the sequence/picture level. In one variation, the delta QP is incorporated or derived only if nonzero quantized transform coefficients exist in a leaf CU that is larger than the QP minimum CU size. In another variation, quantization parameter information is only incorporated or derived when a leaf CU has any nonzero quantized transform coefficient. In yet another variation, a flag is used to indicate whether one delta QP per LCU is transmitted if the LCU has any nonzero quantized transform coefficient or one delta QP per leaf CU is transmitted if the leaf CU has any nonzero quantized transform coefficient. | 05-10-2012 |
20120128060 | Method and Apparatus of Spatial Motion Vector Prediction - An apparatus and method for deriving a motion vector predictor or a motion vector predictor candidate or a motion vector or a motion vector candidate for a current block are disclosed. In video coding systems, the spatial and temporal redundancy is exploited using spatial and temporal prediction to reduce the information to be transmitted or stored. Motion Vector Prediction (MVP) has been used to further conserve the bitrate associated with motion vector coding. The MVP technique being developed for the current HEVC only considers the motion vector having the same reference list and the same reference picture index as the current block to be an available spatial motion vector predictor candidate. It is desirable to develop a MVP scheme that can improve the availability of the motion vector predictor candidate based on motion vectors from the spatially neighboring block. Accordingly, an apparatus and method for determining a motion vector predictor or motion vector predictor candidate or motion vector or motion vector candidate for a current block based on motion vectors associated with reference pictures in list | 05-24-2012 |
20120134415 | Method and Apparatus of Extended Motion Vector Predictor - A method and apparatus for determining a motion vector predictor (MVP) or a MVP candidate based on a MVP set are disclosed. In video coding systems, the spatial and temporal redundancy is exploited using spatial and temporal prediction to reduce the video data to be transmitted or stored. Motion vector prediction has been used to further conserve the bitrate associated with motion vector coding. Motion vector prediction technique being developed for the current high efficiency video coding (HEVC) only uses a MVP candidate set including spatial MVP candidates and a temporal candidate corresponding to the co-located block. In the current disclosure, the spatial and temporal motion vector predictor set is extended to include at least one spatially neighboring block associated with list 0 reference pictures and list 1 reference pictures, and co-located block and its neighboring block associated with list 0 reference pictures and list 1 reference pictures. | 05-31-2012 |
20120134416 | Method and Apparatus for Derivation of MV/MVP Candidate for Inter/Skip/Merge Modes - A method and apparatus for deriving a temporal motion vector predictor (MVP) are disclosed. The MVP is derived for a current block of a current picture in Inter, or Merge, or Skip mode based on co-located reference blocks of a co-located block. The co-located reference blocks comprise an above-left reference block of the bottom-right neighboring block of the co-located block. The reference motion vectors associated with the co-located reference blocks are received and used to derive the temporal MVP. Various configurations of co-located reference blocks can be used to practice the present invention. If the MVP cannot be found based on the above-left reference block, search for the MVP can be continued based on other co-located reference blocks. When an MVP is found, the MVP is checked against the previously found MVP. If the MVP is the same as the previously found MVP, the search for MVP continues. | 05-31-2012 |
20120177103 | APPARATUS AND METHOD OF EFFICIENT SAMPLE ADAPTIVE OFFSET - For sample adaptive offset, classification may be used to classify the pixels into multiple categories and pixels in each category are offset compensated using an offset value for the category. The classification may be based on values of the current pixel and its neighboring pixels before SAO compensation. Therefore, the SAO compensated pixel cannot be written back to the current pixel location until the category for all pixels are determined. An embodiment of the present invention stores the relation between the current pixel and said one or more neighboring pixels so that the SAO compensated current pixel can replace the current pixel without buffering the to-be-processed pixels for classification. The SAO process may be performed on a region by region basis to adapt to the local characteristics of the picture. Rate-distortion optimization (RDO) is often used to guide the mode decision, such as region splitting/region merging decision. Computations associated with the RDO process usually are very computational intensive. Accordingly, distortion reduction estimation is developed which can substantially reduce the required computation associated with RDO. | 07-12-2012 |
20120177107 | Apparatus and Method of Sample Adaptive Offset for Video Coding - An apparatus and method for sample adaptive offset to restore intensity shift of processed video data are described. In a video coding system, the video data are subject to various processing such as prediction, transformation, quantization, deblocking, and adaptive loop filtering. Along the processing path in the video coding system, certain characteristics of the processed video data may be altered from the original video data due to the operations applied to video data. For example, the mean value of the processed video may be shifted. Therefore, the pixel intensity shift has to be carefully compensated or restored to alleviate the artifacts. Accordingly a sample adaptive offset scheme is disclosed that can take into consideration of the dynamic characteristics within a frame using a region partition scheme. Furthermore, the sample adaptive offset scheme also supports multiple SAO types that can be tailored to the characteristics of processed video data and achieve better quality. | 07-12-2012 |
20120207227 | Method and Apparatus for Slice Common Information Sharing - A method and apparatus for sharing information in a video coding system are disclosed. Embodiments according to the present invention use an information sharing flag to determine whether to share in-loop filter information in the picture level. The information sharing flag may be incorporated in the sequence level, the picture level or the slice level to indicate whether information sharing is enabled. Multiple information sharing flags may also be used to adaptively control information sharing. Furthermore, method and apparatus of using multiple Adaptation Parameter Sets (APSs) for information sharing of in-loop filters are disclosed. APS identifiers of in-loop filters may be incorporated in the slice header to allow each of the in-loop filters select respective filter information from the multiple APSs. A flag is incorporated in SPS to indicate whether multiple APS or single APS is used. Various exemplary syntax designs are disclosed to illustrate information sharing. | 08-16-2012 |
20120236941 | Method and Apparatus for Derivation of Spatial Motion Vector Candidate and Motion Vector Prediction Candidate - An apparatus and method for deriving a motion vector predictor are disclosed. In video coding systems, the spatial and temporal redundancy is exploited using spatial and temporal prediction to reduce the information to be transmitted or stored. Motion vector prediction has been used to further conserve the bitrate associated with motion vector coding. In a conventional coding system, a motion vector predictor (MVP) is selected from the spatial MVPs and temporal MVP. The spatial MVP according to a conventional approach is based on motion vectors (MVs) of neighboring blocking pointing to a target reference picture in a given reference list. Embodiments according to the present invention perform the MVP search among an extended search set including MVs pointing to other reference pictures in the given reference list or the other reference list and MVs pointing to the target reference picture in the given reference list or the other reference list. Other aspects of the present invention address the search order of the search set and configuration of neighboring blocks. | 09-20-2012 |
20120236942 | Method and Apparatus for Deriving Temporal Motion Vector Prediction - A method and apparatus for deriving a temporal motion vector predictor (MVP) are disclosed. The MVP is derived for a current block of a current picture in Inter, or Merge, or Skip mode based on co-located reference blocks of a co-located block and a flag is used to indicate the co-located picture. More than one co-located reference blocks can be used to derive the temporal MVP and the co-located reference blocks can be selected from the co-located block as well as neighboring blocks of the co-located block. A search set comprises search motion vectors associated with the co-located reference block(s) is formed. The search motion vector (MV) corresponding to the co-located reference block in the same reference list is searched before the search MV in a different reference list. Various schemes to accommodate implicit method of deriving co-located picture are also disclosed. | 09-20-2012 |
20120294353 | Apparatus and Method of Sample Adaptive Offset for Luma and Chroma Components - A method and apparatus for processing reconstructed video using in-loop filter in a video coding system are disclosed. The method uses chroma in-loop filter indication to indicate whether chroma components are processed by in-loop filter when the luma in-loop filter indication indicates that in-loop filter processing is applied to the luma component. An additional flag may be used to indicate whether the in-loop filter processing is applied to an entire picture using same in-loop filter information or each block of the picture using individual in-loop filter information. Various embodiments according to the present invention to increase efficiency are disclosed, wherein various aspects of in-loop filter information are taken into consideration for efficient coding such as the property of quadtree-based partition, boundary conditions of a block, in-loop filter information sharing between luma and chroma components, indexing to a set of in-loop filter information, and prediction of in-loop filter information. | 11-22-2012 |
20130064472 | Method and Apparatus of High-Resolution Image Reconstruction Based on Multi-Frame Low-Resolution Images - A method and apparatus for reconstructing a high-resolution image based on multiple low-resolution images are disclosed. The method and apparatus incorporating an embodiment according to the present invention reconstructs the high-resolution image based on a kernel regression method using a modified kernel function. The kernel function takes into consideration of registration reliability of regression residue and rotational motion within the multiple low-resolution images. The registration reliability adjusts weighting on the regression residues according to local gradient estimated between neighboring values. Furthermore, multi-scale regression residue is used to alleviate impact of noise. | 03-14-2013 |
20130128986 | Method and Apparatus of Slice Boundary Padding for Loop Filtering - A method and apparatus for video processing of reconstructed video in a reconstruction loop are disclosed. An embodiment according to the present invention performs padding for the blocks in the slice boundaries according to a processing order. Each of the one or more reconstructed blocks at slice boundaries is padded according to a padding order. In-loop filtering is applied to the reconstructed slice according to the processing order, wherein the reconstructed slice is filtered by referencing the one or more padded blocks. The padding order can be vertical-edge first and then horizontal-edge, or horizontal-edge first and then vertical-edge. Various embodiments are disclosed regarding whether padding for a later padded block in the processing order is skipped or not in the overlapped area. The present invention is also applied to adaptation blocks for block-based in-loop filtering in slice boundaries. | 05-23-2013 |
20130259117 | Method and Apparatus of Adaptive Loop Filtering - A method and apparatus for processing of coded video using adaptive offset (AO) are disclosed. Embodiments of the present invention divide reconstructed video data into multiple filter units and apply adaptive offset to the filter units to generate filtered video data, where boundaries of filter units correspond to boundaries of coding units and each of said filter units contains at least one coding unit. Furthermore, two or more of the multiple filter units can be merged as indicated by a merge index to share the applied adaptive offset. A filter control flag can be used to indicate filter ON/OFF control. The luma and chroma components may also share the same filter information. In another embodiment, the filter information sharing among filter units can be applied regardless whether the boundaries of the filter units are aligned with the boundaries of the coding units. | 10-03-2013 |
20130266061 | Method and Apparatus of Deblocking Filter - A method and apparatus for improved deblocking filter are disclosed. In one embodiment according to the present invention, determining the non-zero transform coefficients existence for a PU-only boundary is skipped and therefore the deblocking filter for PU-only boundary is eliminated if the condition of boundary strength equal to 1 is not fulfilled to avoid unnecessary deblocking. In another embodiment of the present invention, three gradients are determined for two pixel lines and filter ON/OFF decision is made based on the three gradient values of the two pixel lines. One aspect of the invention is related to filter strength selection between strong and weak filters. According to one embodiment, the filter strength selection is based on various gradient values of a pixel line across the block boundary. Another aspect of the invention is related to the weak filter. | 10-10-2013 |
20130322523 | METHOD AND APPARATUS FOR REDUCTION OF IN-LOOP FILTER BUFFER - A method and apparatus for in-loop processing of reconstructed video are disclosed. The method and apparatus configure the in-loop processing so that the processing requires no pixel or reduced pixels from other side of a virtual boundary. When the in-loop processing of the to-be-processed pixel requires a pixel from the other side of the virtual boundary, the pixel from the other side of the virtual boundary is replaced by a replacement pixel. The in-loop processing can also be configured to skip the pixel when the processing requires a pixel from other side of the virtual boundary. The in-loop processing can also be configured to change ALF filter shape or filter size when the in-loop processing requires a pixel from other side of the virtual boundary. A filtered output can be combined linearly or nonlinearly with the to-be-processed pixel to generate a final filter output. | 12-05-2013 |
20130322527 | Method and Apparatus for Quantization Level Clipping - A method and apparatus for clipping a transform coefficient are disclosed. Embodiments according to the present invention avoid overflow of the quantized transform coefficient by clipping the quantization level adaptively after quantization. In one embodiment, the method comprises generating the quantization level for the transform coefficient of a transform unit by quantizing the transform coefficient according to a quantization matrix and quantization parameter. The clipping condition is determined and the quantization level is clipped according to the clipping condition to generate a clipping-processed quantization level. The clipping condition includes a null clipping condition. The quantization level is clipped to fixed-range represented in n bits for the null clipping condition, where n correspond to 8, 16, or 32. The quantization level may also be clipped within a range from −m to m−1 for the null clipping condition, where m may correspond to 128, 32768, or 2147483648. | 12-05-2013 |
20140003495 | Method and Apparatus of Scalable Video Coding | 01-02-2014 |
20140072033 | Method and Apparatus of Scalable Video Coding - A method and apparatus for scalable video coding are disclosed, wherein the video data is configured into a Base Layer (BL) and an Enhancement Layer (EL) and wherein the EL has higher spatial resolution or better video quality than the BL. According to embodiments of the present invention, information from the base layer is exploited for coding the enhancement layer. The information coding for the enhancement layer includes CU structure, motion information, motion information, MVP/merge candidates, intra prediction mode, residual quadtree information, texture information, residual information, context adaptive entropy coding, Adaptive Lop Filter (ALF), Sample Adaptive Offset (SAO), and deblocking filter. | 03-13-2014 |
20140086323 | METHOD AND APPARATUS FOR CODING OF INTRA PREDICTION MODE - Embodiments according to the present invention configure the intra prediction mode candidates into multi-level MPM sets, which comprise at least a first-level MPM set and a second-level MPM set. Encoding or decoding a current intra prediction mode is based on the multi-level MPM sets, where one syntax element of the syntax information to be generated or decoded respectively is associated with evaluating the current intra prediction mode using the first-level MPM set. A method and apparatus for spectively is associated with evaluating the current intra prediction mode using the first-level MPM set. A method and apparatus for chroma intra prediction mode encoding and decoding are also disclosed. The chroma intra prediction mode set includes a Luma-based chroma prediction Mode (LM), a Direct Mode (DM) and four other modes. The codeword set comprises variable-length codewords and fixed-length codewords, and the fixed-length codewords are longer than the variable-length codewords. The variable-length codewords are used for the DM and LM, and the fixed-length codewords are used for the four other modes. | 03-27-2014 |
20140086502 | METHOD AND APPARATUS OF CHROMA INTRA PREDICTION WITH REDUCED LINE MEMORY - A method and apparatus for chroma intra prediction for a current chroma block with reduced line memory requirement are disclosed. The chroma intra predictor is derived from reconstructed luma pixels of a current luma block using a model with parameters. In various embodiments according to the present invention, the derivation of the parameters relies on a reconstructed luma pixel set corresponding to neighboring reconstructed luma pixels from causal luma neighboring areas of the current luma block, wherein said causal luma neighboring areas include a first area corresponding to reconstructed luma pixels above a horizontal luma block boundary on a top side of the current luma block, and wherein the reconstructed luma pixels from the first area that are included in the reconstructed luma pixel set are from a luma pixel line immediately above the horizontal luma block boundary. | 03-27-2014 |
20140092980 | METHOD AND APPARATUS OF DIRECTIONAL INTRA PREDICTION - A method and apparatus for intra prediction for a current block using directional intra prediction based on neighboring pixels around the current block are disclosed. Embodiment according to the present invention derives the gradient for the current pixel from the neighboring reconstructed pixels along a prediction direction of directional intra prediction. The gradient derived is used to form the final intra prediction. In another embodiment of the present invention, the intra prediction for slant vertical and horizontal directions is derived based on the neighboring reconstructed pixels in a neighboring row adjacent to the top side of the current block and the neighboring reconstructed pixels in a neighboring column adjacent to the left side of the current block. | 04-03-2014 |
20140119439 | METHOD AND APPARATUS OF INTRA MODE CODING - Method and apparatus for intra prediction mode coding and decoding are disclosed. In one embodiment, the encoding and decoding process assigns individual indices and codewords to DC mode and Planar mode respectively. The flag is set if the current intra prediction mode is equal to any of one or more neighboring intra prediction modes. Variable length codes are designed for a remaining mode set. If the flag is not set, the currently intra prediction mode is encoded using the variable length codes. In another embodiment, multiple most probable modes are used. If the current intra prediction mode is not equal to any of the multiple most probable modes, the current intra prediction mode is encoded using variable length codes designed for the corresponding remaining modes according the ranking order of the remaining modes. | 05-01-2014 |
20140140404 | METHOD AND APPARATUS FOR INTRA PREDICTION USING NON-SQUARE BLOCKS - A method and apparatus for Intra prediction of a block based on neighboring pixels around the block are disclosed. Embodiments according to the present invention use square blocks as well as non-square blocks for Intra prediction. For a 2N×2N Luma CU (coding unit), the CU can be partitioned into 2N×N, N×2N, 2N×2N or N×N PUs. The 2N×N and N×2N PUs can be further processed by either square transforms only or both non-square and square transforms. In one embodiment, the 2N×N PU or the N×2N PU is processed as two N×N TUs (transform units) and each of the N×N TU is further split into smaller N×N TUs based on quad-tree split. In another embodiment, the 2N×N and N×2N PUs are processed as two 2N×0.5N and 0.5N×2N TUs respectively. | 05-22-2014 |
20140146891 | Method and Apparatus of Scalable Video Coding - A method and apparatus for scalable video coding are disclosed, wherein the video data is configured into a Base Layer (BL) and an Enhancement Layer (EL) and wherein the EL has higher spatial resolution or better video quality than the BL. According to embodiments of the present invention, information from the base layer is exploited for coding the enhancement layer. The information coding for the enhancement layer includes CU structure, motion information, motion information, MVP/merge candidates, intra prediction mode, residual quadtree information, texture information, residual information, context adaptive entropy coding, Adaptive Lop Filter (ALF), Sample Adaptive Offset (SAO), and deblocking filter. | 05-29-2014 |