Controlling the computational complexity to balance video quality and computation power consumption in motion estimation is a significant issue. This paper proposes a fast multi-path motion estimation algorithm for ac...
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Controlling the computational complexity to balance video quality and computation power consumption in motion estimation is a significant issue. This paper proposes a fast multi-path motion estimation algorithm for achieving computational complexity reduction as well as controllable computation. First, an enhanced interested diamond search pattern with search point reduction is proposed. In addition, the multi-path search concept is further combined in our proposal to search for the best matched block without suffering from the drawback of being trapped at the local minimum. Finally, by combining the adaptive threshold for early termination, the computation and coding performance can be adaptively controlled by our proposed algorithm to satisfy the various needs of video encoders. Experimental results show that the proposed algorithm with the ability of computation control can give better performance than the diamond search and its multi-path combined algorithm.
The performance of vehicular ad hoc networks (VANETs) is subject to frequent changes due to node mobility so that nonstationary/transient network behavior always exists. In addition, safety applications in VANETs are ...
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The performance of vehicular ad hoc networks (VANETs) is subject to frequent changes due to node mobility so that nonstationary/transient network behavior always exists. In addition, safety applications in VANETs are very sensitive to the real-time performance of delay and packet delivery ratio (PDR). Although there are extensive studies on the steady-state (SS) performance analysis of vehicular networks, little work exists on evaluating their time-varying behavior. In this paper, we develop a performance model to efficiently estimate the dynamic behavior of VANETs. In this paper, vehicle's transmission queue is modeled using fluid-flow (FF)-based differential equations, which are solved using numerical methods, whereas the network hearing topology is modeled by a time-varying adjacency matrix that can be determined from stochastic models, measurements, or discrete event simulations. Numerical results illustrate that our performance model is able to promptly respond to the ongoing dynamic conditions of VANETs and provide reasonably accurate performance results.
This paper presents a strategy that efficiently allocates the limited resource and still maintains the coding performance for the spatial scalability of H.264/SVC. An integrated computation-scalable algorithm is propo...
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This paper presents a strategy that efficiently allocates the limited resource and still maintains the coding performance for the spatial scalability of H.264/SVC. An integrated computation-scalable algorithm is proposed on the basis of priority-based mode decision (PBMD) and activity-based motion estimation (ABME). The rate-distortion cost (RD-cost) of base layer is utilized as the priority to decide the mode in the enhancement layer, and the motion vector difference (MVD) in the base layer is employed to determine the search range as well. Through the proposed approach, computation complexity of the enhancement layer could be reduced efficiently and well allocated. A fast algorithm with early termination mechanism is also proposed in this paper. Experimental results demonstrate that the various rate-distortion and time-saving performances with computation scalability are realized.
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