SYMMETRY FOR INTERPOLATION FILTERING OF SUB-PIXEL POSITIONS IN VIDEO CODING

摘要

This disclosure describes filteringtechniques applied by an encoder and a decoderduring the prediction stage of a video encoding and/ordecoding process. The filtering techniques mayenhance the accuracy of predictive data used duringfractional interpolation, and may improve predictivedata of integer blocks of pixels. There are severalaspects to this disclosure, including a useful twelve-pixel filter support that may be used for interpolation,techniques that use coefficient symmetry andpixel symmetry to reduce the amount of data neededto be sent between an encoder and a decoder toconfigure the filter support for interpolation, andtechniques for filtering data at integer pixel locations in amanner that is similar to sub-pixel interpolation. Otheraspects of this disclosure concern techniques forencoding information in the bitstream to convey thetype of filter used, and possibly the filter coefficientsused. Predictive coding of filter coefficients is alsodescribed.