Directional Filtering for Upsampling According to Direction Information of the Base Layer in the JVT/SVC Codec

Abstract

Abstract. When the reconstructed image of the base layer is up-sampled for decoding the enhancement layer of spatial scalability, direction information derived during decoding the spatially lower layer is used. That is direction information used for Intra prediction which is used for up-sampling again. In most cases, it shows 0.1-0.5dB quality improvement in images up-sampled by using directional filtering compared to those up-sampled conventionally. The same interpolation algorithm should be used in both the encoder and decoder.

Scalable Video Coding with Interlayer Signal Decorrelation Techniques

“…An alternative approach to improve the compression efficiency of enhancement layers is to employ better interlayer predictions. To that end, several techniques have already been proposed to the JVT [6][7][8]. In [6], optimal upsamplers are designed which depend on the downsampling filter, the quantization levels of the base layer, and the input video sequence.…”

“…Later, a family of downsamplers is constructed to span a range of filter lengths, aliasing, and ringing characteristics available to an encoder [7], together with their corresponding upsamplers. In [8], the direction information of the base layer is used to improve the prediction for the macroblocks (MBs) with high-directional characteristics.…”