A fast algorithm to find the region-of-interest in the compressed MPEG domain

We propose a fast, yet simple algorithm to find the region of interest (ROI) from a compressed MPEG video bitstream, with partial decoding. We have used the properties of the human visual system (HVS), applied in the DCT domain, to extract the ROIs. Though a lot of work has been done to obtain ROIs in images based on the HVS, all these systems work in the pixel domain. However, finding the ROIs in the compressed domain has wide applications such as emphasizing perceptually important regions while transrating, defining descriptors for encoded video (MPEG-7), changing image size to adapt to heterogeneous client displays, etc.