Visual Quality Enhancement in DCT-Domain Spatial Downscaling Transcoding Using Generalized DCT Decimation

In this paper, we propose a generalized discrete cosine transform (DCT) decimation scheme for DCT-domain spatial downscaling which performs two-fold decimation on subframes of a flexible size larger than the traditional 8 times 8 block size to improve the visual quality. Efficient sparse-matrix representations are then derived to reduce the computation of… (More)