New Half-Pixel Accuracy Motion Estimation Algorithms for Low Bitrate Video Communications

Fractional-pixel accuracy motion estimation (me) has been shown to result in higher qualityreconstructed image sequences in hybrid video coding systems, however, the higher quality isachieved by notably increased motion field (mf) bitrate and more complex computations, in thispaper, new half-pixel block matching me algorithms are proposed to improve the rate-distortioncharacteristics of low bitrate video communications, the proposed methods tend to decrease therequired video bandwidth, while improving the motion compensation quality, the key idea is toput a deeper focus on the search origin of the me process, based on center-bias characteristicsof low bitrate video mfs, to employ the benefits of mesh-based me (mme), the introducedalgorithms are also examined in the framework of a fast mme scheme. experimental resultsshow the efficiency of the proposed schemes, especially when employed in the mmea pproach,so that a reduction of more than 20% in the mf bit rate is achieved when employing typicalqcif formatted image sequences