Patent · US Expired

Noise reduction in an image

US5825846A · kind A · utility

23Cited by

3References

20Claims

0Family size

Assignee

U.S. Philips Corporation · US

Inventors

Til Aach · Aachen, DE
Dietmar W. Kunz · Aachen, DE

Key dates

Filing date	Dec 20, 1996
Grant date	Oct 20, 1998
Priority date	—
Expiry date	Dec 20, 2016

Classification

Technology area (CPC G)Physics
CPC primaryG06T5/20
WIPO fieldComputer technology
WIPO sectorElectrical engineering

Abstract

In a method of processing an image the image is divided in one or more blocks. Separate blocks are spatially frequency transformed in that pixel-values of the blocks are transformed into spectral coefficients. A noise level of the image is estimated and reduced spectral coefficients are derived from spectral coefficients and the estimated noise level. Pixel-values for a processed block are synthesized from the reduced spectral coefficients and the processed blocks are assembled into a processed image. The noise level is estimated from the image information within the image. Preferably, a few parameters relating to the circumstances under which the image was acquired are also taken into account for estimating the noise level.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.