Comparison between block-based and pixel-based temporal interpolation for video coding

In very low bit rate (VLBR) video conferencing and videotelephony applications, the bit rate of sending video sequences must be kept low due to the limited channel bandwidth. To satisfy the VLBR requirement, temporal subsampling is a simple technique which may be combined with other compression schemes to achieve very large compression ratio. A previous proposed block-based motion compensated temporal interpolation (MCTI) (1995, 1996) can interpolate frames with reasonably good visual qualify but also with some blocking artifacts. In this paper, the block based MCTI is compared with a pixel-based approach. While the pixel-based approach has good performance in some test cases, it is highly computationally intensive making it rather unpractical. It is also found to perform poorly in some sequences.