Fast region-of-interest transcoding for JPEG 2000 images

The paper presents a newly developed region-of-interest (ROI) transcoding method for JPEG 2000 images; it can be used for many progressive image/video streaming applications. The proposed method takes advantage of the empty packet property provided by the JPEG 2000 standard to elevate the priority of the ROI. Based on the user specified ROI information and progressive parameters, the developed transcoder extracts the selected ROI and background packets at the desired quality and suppresses the unselected packets to a low quality. Since the transcoder only performs a reorganization of the packets in the original coded bitstream, it does not involve any re-encoding operation. Compared to other ROI coding schemes in the literature, the proposed method has the advantages of lower complexity and faster processing. Therefore, it is very suitable for real-time applications.