Disclosed are a method and a apparatus for encoding a video, and a method and apparatus for decoding a video, in which neighboring pixels used to perform intra prediction on a current block to be encoded are filtered and intra prediction is performed by using the filtered neighboring pixels.

Method and apparatus for encoding video, and method and apparatus for decoding video

An apparatus for processing a video signal and method thereof are disclosed. The present invention includes receiving prediction mode information, interpolating information and a residual of a current block, reconstructing an interpolating pixel using the interpolating information and a neighbor block, and reconstructing the current block using the interpolating pixel, the prediction mode information and the residual, wherein the interpolating information is generated based on a location of the current block. According to an apparatus and method for processing a video signal, high reconstruction rate can be obtained by improving the related art method having limited intra prediction modes available for a current block located on a boundary area of a picture in encoding in a manner of reconstructing and using an interpolating pixel based on interpolating information.

A method and an apparatus for processing a video signal

This disclosure describes techniques for coding transform coefficients associated with a block of residual video data in a video coding process. Aspects of this disclosure include the selection of a scan order for both significance map coding and level coding, as well as the selection of contexts for entropy coding consistent with the selected scan order. This disclosure proposes a harmonization of the scan order to code both the significance map of the transform coefficients as well as to code the levels of the transform coefficient. It is proposed that the scan order for the significance map should be in the inverse direction (i.e., from the higher frequencies to the lower frequencies). This disclosure also proposes that transform coefficients be scanned in subsets as opposed to fixed subblocks. In particular, transform coefficients are scanned in a subset consisting of a number of consecutive coefficients according to the scan order.

Coding of transform coefficients for video coding

A higher coding efficiency for coding a significance map indicating positions of significant transform coefficients within a transform coefficient block is achieved by the scan order by which the sequentially extracted syntax elements indicating, for associated positions within the transform coefficient block, as to whether at the respective position a significant or insignificant transform coefficient is situated, are sequentially associated to the positions of the transform coefficient block, among the positions of the transform coefficient block depends on the positions of the significant transform coefficients indicated by previously associated syntax elements. Alternatively, the first-type elements may be context-adaptively entropy decoded using contexts which are individually selected for each of the syntax elements dependent on a number of significant transform coefficients in a neighborhood of the respective syntax element, indicated as being significant by any of the preceding syntax elements.

Coding of significance maps and transform coefficient blocks

The emerging international standard for multiview video coding (MVC) is an extension of H.264/advanced video coding. In the joint mode of MVC, both motion estimation (ME) and disparity estimation (DE) are included in the encoding process. This achieves the highest coding efficiency but requires a very high computational complexity. In this letter, we propose a fast ME and DE algorithm that adaptively utilizes the inter-view correlation. The coding mode complexity and the motion homogeneity of a macroblock (MB) are first analyzed according to the coding modes and motion vectors from the corresponding MBs in the neighbor views, which are located by means of global disparity vector. According to the coding mode complexity and the motion homogeneity, the proposed algorithm adjusts the search strategies for different types of MBs in order to perform a precise search according to video content. Experimental results demonstrate that the proposed algorithm can save 85% computational complexity on average, with negligible loss of coding efficiency.

View-Adaptive Motion Estimation and Disparity Estimation for Low Complexity Multiview Video Coding

In this paper, a Context-based 2D Variable Length Coding (C2DVLC) method for coding the transformed residuals in AVS video coding standard is presented. One feature in C2DVLC is the usage of multiple 2D-VLC tables and another feature is the usage of simple Exponential-Golomb codes. C2DVLC employs context-based adaptive multiple table coding to exploit the statistical correlation between DCT coefficients of one block for higher coding efficiency. Exp-Golomb codes are applied to code the pairs of the run-length of zero coefficients and the nonzero coefficient for lower storage requirement. C2DVLC is a low complexity coder in terms of both computational time and memory requirement. The experimental results show that C2DVLC can gain 0.34dB in average for the tested videos when compared with the traditional 2D-VLC coding method like that used in MPEG-2. And compared with CAVLC in H.264/AVC, C2DVLC shows similar coding efficiency.

Context-based 2D-VLC entropy coder in AVS video coding standard

In this paper, two context-based entropy coding schemes for AVS Part-2 video coding standard are presented. One is Context-based 2D Variable Length Coding (C2DVLC) as a low complexity entropy coding scheme for AVS Part-2 Jizhun profile. C2DVLC uses multiple 2D-VLC tables to exploit the statistical features of DCT coefficients for higher coding efficiency. Exponential-Golomb codes are applied in C2DVLC to code the pairs of the run-length of zero coefficients and the non-zero coefficients for lower storage requirement. The other is Context-based Binary Arithmetic Coding (CBAC) as an enhanced entropy coding scheme for AVS Part-2 Jiaqiang profile. CBAC utilizes all previously coded coefficient magnitudes in a DCT block for context modeling. This enables adaptive arithmetic coding to exploit the redundancy of the high-order Markov process in DCT domain with a few contexts. In addition, a context weighting technique is used to further improve CBAC's coding efficiency. Moreover, CBAC is designed to be compatible to C2DVLC in coding elements which simplifies the implementations. The experimental results demonstrate that both C2DVLC and CBAC can achieve comparable or even slightly higher coding performance when compared to Context-Adaptive Variable Length Coding (CAVLC) in H.264/AVC baseline profile and Context-Based Adaptive Binary Arithmetic Coding (CABAC) in H.264/AVC main profile respectively.

Context-based entropy coding in AVS video coding standard

A novel error concealment method is proposed for two-view based stereoscopic video coding to address the challenging problem of adaptively combining inter-view correlation and temporal correlation. First, the disparity vectors of the lost macroblocks' neighboring macroblocks are used to recover the lost or erroneously received motion or disparity vectors. Then we propose a novel error concealment method based on overlapped block motion and disparity compensation, whose weights are determined by the side match criterion and viewpoints. Simulation results show that the subjective and objective performances of the proposed technique are both superior to those of conventional temporal error concealment methods for stereoscopic video coding.

http://sourcedb.ict.cas.cn/cn/ictthesis/200907/P020090722621200766890.pdf

A Novel Error Concealment Method for Stereoscopic Video Coding

The multi-view video coding improves the coding efficiency by utilizing motion-compensated prediction (MCP) and disparity-compensated prediction (DCP). However, the complexity of the inter frame prediction is very high, especially when the rate-distortion optimization is used. This paper presents a fast inter frame prediction algorithm to reduce the complexity. Firstly the prediction type is decided according to reference frames. Then some unuseful search regions in view direction are removed. Finally a fast inter mode decision strategy is proposed based on the relationship between MCP and DCP. Experimental results verify that the proposed algorithm can greatly increase the speed of prediction with negligible loss of coding efficiency.

A Fast Inter Frame Prediction Algorithm for Multi-View Video Coding

It is well observed that usually the run-length of successive zero coefficients becomes longer and the magnitude of non-zero coefficients gets smaller while the DCT subband frequency increases. Therefore, the probability distributions of level/run combinations should be different at different DCT positions. Based on this observation, an efficient context based 2D-VLC entropy coder, especially designed for 8/spl times/8 DCT, is proposed to exploit this context characteristic. The key element of the proposed coder is to design multiple 2D-VLC tables and each can be used context-adaptively to match different level/run combination probability distributions better. Another key element is the usage of exponential-Golomb codes, which keep the multiple tables with low memory requirement. In terms of coding efficiency, the experimental results show that the proposed method can gain up to 0.23 dB when compared to the one-table-for-one-block coding method.

Qiang Wang

Papers

Context-based 2D-VLC entropy coder in AVS video coding standard

Context-based entropy coding in AVS video coding standard

A Novel Error Concealment Method for Stereoscopic Video Coding

A Fast Inter Frame Prediction Algorithm for Multi-View Video Coding

Context-based 2D-VLC for video coding