Generalized inscale motion compensation framework for spatial scalable video coding In existing video coding schemes with spatial scalability based on pyramid frame representation, such as the ongoing H.264MPEG4 SVC (scalable video coding) standard, video frame at a high resolution is mainly predicted either from the lowerresolution image of the same frame or from the temporal neighboring frames at the same resolution. Most of these prediction techniques fail to exploit the two correlations simultaneously and efficiently. This paper extends the inscale prediction technique developed for wavelet video coding to a generalized inscale motion compensation framework for H.264MPEG4 SVC. In this framework, for a video frame at a high resolution layer, the lowpass content is predicted from the information already coded in lower resolution layer, but the highpass content is predicted by exploiting the neighboring frames at current resolution. In this way, both the crossresolution correlation and temporal correlation are exploited simultaneously, which leads to much higher efficiency in prediction. Preliminary experimental results demonstrate that the proposed framework improves the spatial scalability performance of current H.264MPEG4 SVC. The improvement is significant especially for highfidelity video coding. In addition, another advantage over waveletbased inscale scheme is achieved that the proposed framework can support arbitrary downsampling and upsampling filters.

Subband motion compensation for spatially scalable video coding In this paper, a new enhancement layer motion compensation technique referred to as subband motion compensation is proposed for spatially scalable video coding. This approach is proposed as an alternative to a technique which we call pyramid motion compensation in this paper and which is referred to as interlayer residual prediction in the H.264MPEG4AVC scalable extension, Scalable Video Coding (SVC) standard. The main difference between these two techniques lies in the way they use the base layer information to encode the enhancement layer. Experimental results comparing the two approaches show that for enhancement layer encoding, pyramid method is better when the corresponding base layer is encoded with a lower bitrate while subband method outperforms pyramid method when the base layer has a higher bitrate. This motivates future proposed work to adaptively choose between these two methods at the macroblock level or even at the transform coefficient level for spatially scalable video coding.