Recursive filtering a video image using activity mapping
US8139649B2 · kind B2 · utility
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14Claims
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Key dates
| Filing date | May 2, 2007 |
| Grant date | Mar 20, 2012 |
| Priority date | — |
| Expiry date | Jan 18, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/21
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of recursive filtering a video image includes determining a local variance σ2 in luminosity in the vicinity of a picture element on the image; making an estimate of a value of noise variance σr2; obtaining a surface for value of a proportional parameter K from the equationwhere 1≦σ≦128, 1 ≦σr≦64 and ρ, τ, α, and β are empirical constants, and selecting a value of λ to scale a relative contribution to the value of K by the luminosity variance and the noise variance. The image is recursively filtered using the proportional parameter K to sum proportions of the current image and an immediately preceding image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.