An effective motion vector re-estimation method for low bit-rate video transcoding

For the low bit-rate multimedia communications, video contents have to be transcoded according to the requirements of network bandwidth and the performance of clients. However, transcoding to the low bit-rate creates video quality degradation (drift error) caused by quantization, motion vector truncation, and downsizing. In this paper, we present an effective motion vector re-estimation method to compensate drift errors in the spatial resolution reduction transcoding. Experimental results show that our method can preserve image quality while transcoding to the low bit-rate.