Motion-adapted content-based temporal scalability in very low bitrate video coding
Summary form only given. Because of stringent bandwidth requirement, very low bitrate video coding usually uses lower frame rates in order to comply with the bitrate constraint. With a reasonably low frame rate, it can reserve basic visual information of an image sequence. However, on special occasions or for specific human understanding purposes, it can barely provide enough temporal resolution. In these cases, we would apply content-based temporal scalability to enhance temporal resolution for desired objects/areas in an image, with a reasonable increase of bitrate. We propose a motion-adapted encoding scheme for content-based temporal scalability in very low bitrate video coding. This coding scheme selectively encodes desired objects and makes proper adjustment to the rest of the scene. Content-based scalability and temporal scalability are achieved via two separate coding steps. This coding scheme is efficient for image sequences with hierarchical structure, such as sequences with background motion and sequences with single moving object. Simulations are done on videotelephony sequences and selected MPEG4 test sequences.