Arbitrary downsizing video transcoding using fast motion vector reestimation

We propose a video transcoding method for arbitrarily downsizing a precoded video by reestimating from its original motion vectors the new motion vectors required to code the downsized video. Compared with the existing methods for downsizing a precoded video by an integral factor, the main advantage of the proposed method is that the spatial resolution of the precoded video can be freely adjusted to meet different bandwidth and device requirements. Experimental results show that the proposed method can obtain arbitrarily downsized video with good perceptual quality while reducing the computational complexity of the process.