Approximate bicubic filter
AssigneeMicrosoft Corporation
InventorSridhar Srinivasan
Life of this patent
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Abstract
Various techniques and tools for approximate bicubic filtering are described. For example, during motion estimation and compensation, a video encoder uses approximate bicubic filtering when computing pixel values at quarter-pixel positions in reference video frames. Or, during motion compensation, a video decoder uses approximate bicubic filtering when computing pixel values at quarter-pixel positions.
Claims20
In a computer system, a computer-implemented method comprising:
- computing a value at a quarter-sample position using an approximate bicubic filter, wherein the approximate bicubic filter performs substantially like a pure bicubic filter but has different filter coefficients than a pure bicubic filter and/or lower resolution than the pure bicubic filter.
A computer-readable medium storing computer-executable instructions for causing a computer system programmed thereby to perform a computer-implemented method of sub-pixel interpolation in plural reference video frames, the method comprising:
- at each of plural sub-pixel positions, computing a pixel value using an approximate bicubic filter, including, for each of plural sub-pixel positions in a first reference video frame, using the approximate bicubic filter in at least one stage of two-stage interpolation.
A system comprising:
- means for computing a pixel value at a quarter-pixel position in a reference video frame using an approximate bicubic filter, wherein the approximate bicubic filter has bicubic-like performance but has lower resolution than a pure bicubic filter;
- means for performing motion compensation relative to the reference video frame.
Dependencies are inferred from the claim text.