The waveletbased multiresolution motion estimation using temporal aliasing detection In this paper, we propose a new algorithm for waveletbased multiresolution motion estimation (MRME) using temporal aliasing detection (TAD). In wavelet transformed imagevideo signals, temporal aliasing will be severe as the motion of object increases, causing the performance of the conventional MRME algorithms to drop. To overcome this problem, we perform the temporal aliasing detection and MRME simultaneously instead of using a temporal antialiasing filter which changes the original signal. We show that this technique gives competitive or better performance in terms of ratedistortion (RD) for slowvarying or simplemoving video signals compared to conventional MRME employing increased search area (SA).

A double motioncompensated orthogonal transform with energy concentration constraint This paper discusses a transform for successive pictures of an image sequence which strictly maintains orthogonality while permitting 2hypothesis motion compensation between pairs of pictures. We extend previous work on an orthogonal transform for image sequences which uses only 1hypothesis motion compensation between pairs of pictures. This work is motivated by the well known fact that the motioncompensated lifted Haar wavelet maintains orthogonality only approximately. In the case of zero motion fields, the motioncompensated lifted Haar wavelet is known to be orthogonal. But for complex motion fields with many multiconnected and unconnected pixels, the motioncompensated lifted Haar wavelet cannot accurately maintain its transform property and, hence, suffers a performance degradation. The presented double motioncompensated orthogonal transform strictly maintains orthogonality for any motion field. For the transform, each pixel in the highband is compensated by a linear combination of two motioncompensated pixels chosen from the corresponding lowband. That is, each pixel in the highband is associated with two motion vectors. This is in contrast to the previously presented single motioncompensated orthogonal transform where each pixel in the highband is compensated by only one motioncompensated pixel chosen from the corresponding lowband. In terms of energy concentration, the double motioncompensated orthogonal transform outperforms the single motioncompensated orthogonal transform and compares favorably with the double motioncompensated lifted Haar wavelet.