Inter Layer Spatial Interpolation Based on Component-Separable Filter Design

Scalable video coding is a new emerging standard, which provides scalability at the bit stream level with good compression efficiency and allowing free combinations of spatial, temporal and quality scalability. In current working draft (WD), a uniform up-sampling filter is employed to interpolate the base layer frames. This technique achieves high interpolated precision for both luma component and chroma components, but it results in extremely large encoding time which obstructs it from practical use. This paper proposes an inter layer spatial interpolation based on component-separable filter design, which makes use of a basic characteristic of human vision system and intends to assign different filters for different components. Specifically, current usage of the 6-tap filter is only for luma component, but for chroma components, much more simplified filter such as 2-tap or 4-tap filter, should be used instead. Experimental results show that our proposed scheme can reduce the computational complexity significantly with negligible coding loss and bit-rate increases. As a result, it can be applied in the inter layer spatial interpolation of SVC.