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Fade and dissolve transitions are two of the most frequently used special effects in video non-linear editing (NLE). In this paper, we propose an adaptive motion vector re-sampling (AMVR) algorithm to achieve fast fade and dissolve transitions on MPEG video sequences. Experimental results show that our algorithm greatly reduces the computational complexity while keeping the quality of the reconstructed edited video in comparison with conventional motion vector re-sampling (MVR) algorithms. [ABSTRACT FROM AUTHOR]

A channel estimation method based on frequency-domain pilots and time-domain processing (FPTP) is proposed for OFDM systems in time-varying channels. Through Discrete Fourier Transform (DFT), the channel impulse response (CIR) is estimated by using the frequency-domain pilots, which is equivalent to the CIR estimated by cyclic correlation using time-domain pilot sequence. Hence, the channel estimation error, caused by the spectral leakage of the DFT, can be reduced by canceling the non-idea auto-correlation property of the pilot sequence in time-domain. At the same time, the complicated cyclic correlation computation in time-domain is evitable. The theoretical analysis and simulation results show that the proposed method outperforms the traditional DFT-based method and Wiener filter algorithm in time-varying multi-path fading channels. Moreover, the uncoded bit error rate (BER) performance of proposed algorithm is very close to that with perfect channel knowledge, especially in fast fading channels. [ABSTRACT FROM AUTHOR]