Haverstock & Owens LLP
Parametric loop filter
A parametric loop filter uses a set of fixed filters to remove or reduce noise and artifacts introduced during video coding. The filters are pre-trained offline and hardwired into encoder and decoder, instead of online trained Wiener filters. The filters are able to be specified using one or more parameters including: direction, bandwidth along the direction (bw//) and bandwidth perpendicular to the direction (bw⊥). The filter to be used is able to be derived from local image characteristics or predicted from neighboring blocks. The parametric loop filter utilizes much less computation, delay and memory access at the encoder. Fixed coefficients allow fast implementation of filtering at the decoder. A parametric loop filter is able to be combined with online training to further improve performance, by allowing one or more fixed filters to be replaced with online trained Wiener filters.
Sony Corporation
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Lina Ehsan Wei
Dong Maani Liu