Resampling and picture resizing operations for multi-resolution video coding and decoding
First Claim
1. In a computer system that implements a video encoder or video decoder, a method comprising:
- determining one or more bandwidth control parameters, wherein a syntax element in a bitstream of encoded data indicates the one or more bandwidth control parameters;
based at least in part on the one or more bandwidth control parameters and phase information, computing plural filter tap values of an upsampling filter;
buffering video picture data at a first spatial resolution;
upsampling at least part of the video picture data to a second spatial resolution higher than the first spatial resolution using the upsampling filter; and
using the upsampled video picture data for prediction of sample values of a picture at the second spatial resolution.
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Accused Products
Abstract
Techniques and tools for high accuracy position calculation for picture resizing in applications such as spatially-scalable video coding and decoding are described. In one aspect, resampling of a video picture is performed according to a resampling scale factor. The resampling comprises computation of a sample value at a position i,j in a resampled array. The computation includes computing a derived horizontal or vertical sub-sample position x or y in a manner that involves approximating a value in part by multiplying a 2n value by an inverse (approximate or exact) of the upsampling scale factor. The approximating can be a rounding or some other kind of approximating, such as a ceiling or floor function that approximates to a nearby integer. The sample value is interpolated using a filter.
171 Citations
22 Claims
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1. In a computer system that implements a video encoder or video decoder, a method comprising:
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determining one or more bandwidth control parameters, wherein a syntax element in a bitstream of encoded data indicates the one or more bandwidth control parameters; based at least in part on the one or more bandwidth control parameters and phase information, computing plural filter tap values of an upsampling filter; buffering video picture data at a first spatial resolution; upsampling at least part of the video picture data to a second spatial resolution higher than the first spatial resolution using the upsampling filter; and using the upsampled video picture data for prediction of sample values of a picture at the second spatial resolution. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. One or more computer-readable media storing computer-executable instructions for causing a processor programmed thereby to perform scalable video coding or scalable video decoding, the one or more computer-readable media being selected from the group consisting of volatile memory, non-volatile memory and magnetic disk, the computer-executable instructions comprising:
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instructions for determining one or more bandwidth control parameters, wherein a syntax element in a bitstream of encoded data indicates the one or more bandwidth control parameters; instructions for, based at least in part on the one or more bandwidth control parameters and phase information, computing plural filter tap values of an upsampling filter; instructions for buffering video picture data at a first spatial resolution; instructions for upsampling at least part of the video picture data to a second spatial resolution higher than the first spatial resolution using the upsampling filter; and instructions for using the upsampled video picture data for prediction of sample values of a picture at the second spatial resolution. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A computer system comprising a processor and memory, wherein the computer system implements:
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a buffer configured to store video picture data at a first spatial resolution; and a video encoder or video decoder configured to; determine one or more bandwidth control parameters, wherein a syntax element in a bitstream of encoded data indicates the one or more bandwidth control parameters; based at least in part on the one or more bandwidth control parameters and phase information, compute plural filter tap values of an upsampling filter; upsample at least part of the video picture data to a second spatial resolution higher than the first spatial resolution using the upsampling filter, wherein the upsampling filter has (a) a single side lobe on each side of a main lobe, (b) a smooth impulse response, and (c) a unity gain DC response; and use the upsampled video picture data for prediction of sample values of a picture at the second spatial resolution. - View Dependent Claims (17, 18, 19, 20, 21, 22)
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Specification