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US 8,803,902 B2Granted
Computing level of detail for anisotropic filtering
AssigneeIntel Corporation
InventorLarry Seiler
Life of this patent
Estimating the term…
Abstract
Anisotropic filtering may be done in graphics processing without actually have to calculate the elliptical weighted averaging ellipse. Instead, an estimate may be used for the length of the minor axis. The estimate avoids the complexities inherent in the elliptical weighted averaging ellipse calculation and reduces overhead, while still obtaining sufficient accuracy.
Claims10
A computer executed method comprising:
- calculating lengths of minor and major axes of an elliptical filter region using two gradient vectors by a hardware graphics processor;
- developing a correction factor for said calculated lengths of minor and major axes by taking the cosine of an angle between the vectors times the square of a ratio of lengths of the vectors and scaling from 0 to 1 to a scaled range of 1 to square root of 2;
- and
- correcting the calculated lengths of minor and major axes to anisotropically filter graphical information by multiplying the correction factor times the major axis length and dividing the correction factor by the minor axis length.
1 more element
A non-transitory computer readable medium storing instructions executed by a computer to:
- calculate lengths of minor and major axes of an elliptical filter region using two gradient vectors;
- develop a correction factor for said calculated lengths of minor and major axes by taking the cosine of an angle between the vectors times the square of a ratio of lengths of the vectors and scale from 0 to 1 to a scaled range of 1 to square root of 2;
- and
- correct the calculated lengths of minor and major axes to anisotropically filter graphical information by multiplying the correction factor times the major axis length and divide the correction factor by the minor axis length.
1 more element
An apparatus comprising:
- a processor to calculate lengths of minor and major axes of an elliptical filter region using two gradient vectors, develop a correction factor for said calculated lengths of minor and major axes by taking the cosine of an angle between the vectors times the square of a ratio of lengths of the vectors and scale from 0 to 1 to a scaled range of 1 to square root of 2, correct the calculated lengths of minor and major axes to anisotropically filter graphical information by multiplying the correction factor times the major axis length and divide the correction factor by the minor axis length;
- and
- a storage coupled to said processor.
Dependencies are inferred from the claim text.