Non-linear up-sampling for image coding in a spatial pyramid

A locally adaptive up-sampling method that improves the efficiency of a spatially scalable representation of images in a spatial pyramid is presented. While linear methods use a globally optimized up-sampling filter design, the method presented locally switches between enhancement of significant structures and smoothing of flat regions that are dominated by noise. It is based on a locally adaptive Wiener filter expression that can be implemented by the bilateral filter. The performance of the method is assessed in a scenario resembling its possible use in MPEG's and ITU-T's joint current activity on scalable video coding (SVC).