Spatially adaptive subsampling of image sequences

In a spatially adaptive subsampling scheme, the subsampling lattice is adapted to the local spatial frequency content of an image sequence. In this paper, we use rate-distortion theory to show that spatially adaptive subsampling gives a better performance than subsampling with a fixed sampling lattice. A new algorithm that optimally assigns sampling lattices to different parts of the image is presented. The proposed spatially adaptive subsampling method can be applied within a motion-compensated coding scheme as well. Experiments show an increased performance over fixed lattice subsampling.