Mediaprocessing in the compressed domain

The emergence of compression standards such as JPEG, MPEG, H.320 and H.324 has enabled many consumer and business multimedia applications wherein the multimedia content is disseminated in their compressed form. Many applications however require processing of the multimedia content prior to presentation. Traditional approaches for processing rely on first decompressing the bitstreams and then applying the desired processing function. We describe developments that have led to processing techniques that can be directly implemented on an intermediate representation of the compressed domain information. By avoiding the computationally expensive decompression and recompression processes needed in traditional spatial/temporal domain based techniques, mediaprocessing in the compressed domain achieves 2-4 fold speedup for typical processing functions such as image downscaling, bitrate conversions, interframe to intraframe conversions.