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This paper proposes the directional filtering transform (dFT, in order to distinguish from the common usage on DFT) to better exploit intra-frame correlation in H.264 intra-frame coding. It consists of a directional filtering and an optional DCT transform. In the proposed directional filtering, there are two different approaches. One is the uni-directional filtering (UDF) that is similar to H.264...
Current view synthesis prediction (VSP) techniques for multiview video coding (MVC) rely on disparity-based view interpolation or depth-based 3D warping. The former cannot be applied to every camera view, whereas the latter may require coding of the depth information of a scene. To avoid these constraints, we propose an improved VSP-based MVC scheme based on the following three techniques: 1) view...
Fractional motion estimation (FME) is widely used in video compression standards. In H.264/AVC, the precision of motion vector is down to quarter pixels to improve the coding efficiency. However, FME occupies over 45% of the computation complexity in an H.264 encoder and this high complexity limits the processing capability. In this paper, a single-iteration full search FME is proposed. By the algorithm...
View interpolation has been applied in multiview view coding. However, existing schemes assume all cameras are aligned. These methods may not perform well when neighboring cameras point to different directions. In this paper, we apply the rectification based view interpolation to MVC. We first derive the theoretical performance gain of the rectification based view interpolation over existing interpolation...
H.264 adopts variable block size motion estimation and rate-distortion-optimization based mode decision to improve video quality and compression ratio. These techniques have made H.264 better than other existing video coding standards. However, they are computationally intensive and time-consuming. In this paper, a fast mode selection scheme is proposed for H.264 inter prediction. Firstly, the first...
Motion estimation is a very time consuming part in H.264 codec. In order to reduce motion estimation time, many strategies have been used during this process. Dynamic search range is one of them. In this paper, based on the analysis of the problems existed in current algorithm, we propose a new strategy to predict motion estimation search range by using the information of image size, block mode and...
Video adaptation has been considered as a promising technique to tackle challenging problems in pervasive multimedia applications. However, the styles of video representation and description in existing framework are not flexible enough to adapt diversified application environment. In this paper, we propose a novel solution based on intermediate description, which can support fast multiple video adaptation...
Scalable Video Coding (SVC) is backwards compatible to H.264/AVC in the sense that the base layer sub-bitstream is decodable by an H.264/AVC decoder. However, there are applications wherein it is desirable for an H.264/AVC decoder to obtain a higher resolution video representation than the base layer within SVC. In order to fulfill the needs of such application scenarios, transcoding of SVC enhancement...
In modern video coding standards, motion compensated prediction (MCP) plays a key role to achieve video compression efficiency. Most of them make use of block matching techniques and assume the motions are pure translational. Attempts toward a more general motion model are usually too complex to be practical in near future. In this paper, a new Block-Matching Translation and Zoom Motion-Compensated...
In this paper, we contribute a configurable SAD tree architecture based on adaptive subsampling scheme. Firstly, by further exploiting the spatial feature, the integer motion estimation process is greatly sped up. Secondly, the conventional partial sum of absolute difference (SAD) based pipeline structure is optimized into configurable SAD oriented way, which enhances the performance and solve the...
Rate control plays a crucial role for video communication applications. It ensures that the generated compressed bit streams satisfy bandwidth and buffer constraints. Rate control algorithms recommended by H.264/AVC adopt rate-distortion (R-D) models for inter-frames to determine quantization parameters (QPs) but not for intra-frames. Instead, they directly compute QPs without any considerations of...
Rate control regulates the output bit rate of a video encoder in order to obtain optimum visual quality within the available network bandwidth and to maintain buffer fullness within a specified tolerance range. In this paper, we propose a novel rate control scheme for H.264/AVC video compression with a number of new features. We first introduce a calculation approach of frame complexity based on the...
This paper proposes a novel fractional compensation approach for spatial scalable video coding. It simultaneously exploits inter layer correlation and intra layer correlation by learning-based mapping. Instead of using an enhancement layer reconstruction as an entire reference, a set of reference pairs are generated from high-frequency components of both base layer and enhancement layer reconstructions...
Although widely used otherwise, MDCT is excluded in the current scheme for spatial cues representation, due to its lacking of phase information and energy conservation. But combining MDCT with MDST overcomes the difficulties. Moreover, MDST spectra can be built perfectly from neighboring MDCT spectra. The MDCT-MDST conversion, in matrix form, is approximating to a banded sparse matrix. When applied...
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