Adaptive filtering

Abstract

A method and device for determining an adaptive filter having multiple filter parameters, wherein a first filter parameter has a first level of adaptivity and a second filter parameter has a second, different level of adaptivity. Parameter values for the first filter parameter are determined among a first set of allowable filter parameter values. Parameter values for the second filter parameter are correspondingly determined among a second, different set of allowable filter parameter values. The different levels of adaptivity in the filter parameters are achieved because the second set includes more allowable filter parameter values than the first set. The adaptive filter is advantageously used in filtering in intra- or inter-predication during video encoding and decoding.

Description

technical field [0001] The present invention relates generally to adaptive filtering, and in particular to adaptive filtering useful in inter and intra prediction applicable to image and video coding. Background technique [0002] Prediction can be used to exploit temporal and spatial redundancy to enable compact representations of video signals. Pixel prediction is an important part of video coding standards such as H.261, H.263, MPEG-4 and H.264 [1]. In H.264, there are three pixel prediction methods used, namely intra prediction, inter prediction and bi-directional prediction. Intra prediction provides spatial prediction of a current block of pixels from previously decoded pixels of the current frame. Inter prediction uses a corresponding but displaced pixel block from a previously decoded frame to give a temporal prediction of the current pixel block. Bidirectional prediction gives a weighted average of the two inter predictions. [0003] The inter-frame prediction m...

AI Technical Summary

Problems solved by technology

This in turn results in a large computational effort when determining the filter coefficients of the filter and when using them to filter the input data

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