No abstract

A scaler is one of the most important modules in various video applications, such as ultra-high definition TV and scalable video systems. A variety of scaling techniques have been used to increase the video quality when the resolution of the source image has to be up- and down-scaled. Some conventional schemes exploit the property of local block data. Others consider the edge information of the data to be scaled. In this paper, we formulate a scaling problem to minimize the information loss resulting from the resizing process. The loss is considered in both the spatial and the frequency domains, and then it is minimized to optimize the kernel of the scaler. The simulation results show that the proposed algorithm reduces the information loss more than conventional schemes. When compared with the conventional algorithms, the proposed method outperforms those with similar complexity.

Distributed video codec (DVC) has been developed to construct a simple encoder that utilizes information theory for distributed sources in the circumstance of mobile multimedia communication. In the DVC codec, an efficient algorithm to generate side information (SI) is one of the most important techniques to improve the coding performance. We propose a scheme to increase the quality of SI frame, where the proposed scheme consists of three steps. In the first step, SI frame is constructed by motion estimation and motion compensation in the DVC decoder. Then, in the second step, the blocks in the temporary SI frame are classified into reliable or unreliable ones. The unreliable blocks are updated by block boundary matching algorithm in the third step. Simulation results show that the proposed algorithm outperforms the conventional methods significantly. In addition, the proposed scheme can be combined with the conventional schemes generating SI frame to increase the coding performance of the DVC codec.

Transcoding between Distributed Video Coding (DVC) and VC-1 is an interesting research topic, has various applications, and VC-1 is one of most popular and efficient video codecs. Among the various techniques related to transcoders, we focus on motion estimation and mode decision. In this paper, we propose a Best Matched Vector Selection (BMVS) and fast mode decision to increase the accuracy and speed of the motion vector estimation and mode decision in the transcoder. BMVS is used to predict motion vectors for multiple reference frames that are far from the current frame. The proposed mode decision scheme selects a mode for the current coding block based on the information transferred from the DVC decoder, without calculating the Rate-Distortion (RD) costs for all possible candidate modes.Simulation results show that the proposed schemes simplify the transcoder significantly without degrading the transcoded video sequences 1 .