Efficient mode decision for noisy video transcoding

Anna Zhang, Zhen Han, Zhongyuan Wang

Abstract: In many practical transcoding applications, such as video surveillance, the source videos are often contaminated by noise. The presence of noise not only results in poor compression efficiency and visual quality, but also imposes an adverse effect on the performance of subsequent video analysis tasks. Thereby it is very necessary to denoise the video. In this paper, we propose an efficient mode decision method for H.264 noisy video transcoding through analysing the effect of noise on mode decision. In the algorithm, we use the information available from previously decoded MBs to decide which modes can be overpassed with little loss to the rate-distortion performance. Experimental results show that our method saves the computational complexity nearly 65%, without noticeable rate-distortion(R-D) loss in comparison with the “Full-coding” (cascaded transcoding) method.