The increasing use of multimedia streams nowadays necessitates the development of efficient and effective methodologies for manipulating databases storing these streams. Content-based access to multimedia databases requires in its first stage to parse the video stream into separate shots. This work proposes a new paradigm capable of detecting scene changes on compressed MPEG video data directly...

We examine the problem of estimating a reverse motion vector eld from a given forward motion vector eld and its motion-compensated residual. This problem has practical importance when providing reverse-play function-ality in compressed video environments, where video data is stored, processed, and transported in compressed form. We present a family of algorithms that trade oo motion vector accu...

Pre-processing algorithms improve on the performance of a video compression system by removing spurious noise and insignificant features from the original images. This increases compression efficiency and attenuates coding artifacts. Unfortunately, determining the appropriate amount of pre-filtering is a difficult problem, as it depends on both the content of an image as well as the target bit-...

The problem of the enhancement of a low bit-rate compressed video sequence using the information provided by the encoder is investigated in this paper. The proposed algorithm is spatio-temporally adaptive and enforces di erent degrees of between-block, within-block, and temporal smoothness of the decompressed frames based on macroblock types. The algorithm uses the projections onto the sets tha...