Structure and method for film grain noise reduction
First Claim
Patent Images
1. A system for processing a video signal, comprising:
- a temporal filter receiving said video signal and providing a temporal noise reduced video signal and a motion signal indicative of motion in said video signal;
a spatial filter receiving said video signal and providing a spatial noise reduced video signal; and
a weighted average circuit receiving said motion signal, said temporal noise reduced video signal and said spatial noise reduced video signal, said weighted average circuit combining said temporal noise reduced video signal and said spatial noise reduced video signal according to said motion signal to provide an output video signal, said output video signal being weighted towards said temporal noise reduced video signal, when said motion signal indicates substantially no motion, and being weighted towards said spatial noise reduced video signal, otherwise.
4 Assignments
0 Petitions
Accused Products
Abstract
A video signal is both spatially and temporally filtered. The output video signal is temporally noise reduced in portions of the image which exhibits little or no motion, and is spatially noise reduced in portions where motion exists. This approach is particularly applicable to reducing film grain noise in video material that originates from images on photographic films, since film grain noise is more correlated spatially than temporally.
144 Citations
14 Claims
-
1. A system for processing a video signal, comprising:
-
a temporal filter receiving said video signal and providing a temporal noise reduced video signal and a motion signal indicative of motion in said video signal; a spatial filter receiving said video signal and providing a spatial noise reduced video signal; and a weighted average circuit receiving said motion signal, said temporal noise reduced video signal and said spatial noise reduced video signal, said weighted average circuit combining said temporal noise reduced video signal and said spatial noise reduced video signal according to said motion signal to provide an output video signal, said output video signal being weighted towards said temporal noise reduced video signal, when said motion signal indicates substantially no motion, and being weighted towards said spatial noise reduced video signal, otherwise. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method for processing a video signal, comprising:
-
temporally filtering said video signal to provide a temporal noise reduced video signal and a motion signal indicative of motion in said video signal; spatially filtering said video signal to provide a spatial noise reduced video signal; and providing a weighted average of said temporal noise reduced video signal and said spatial noise reduced video signal according to said motion signal to provide an output video signal, said output video signal being weighted towards said temporal noise reduced video signal, when said motion signal indicates substantially no motion, and being weighted towards said spatial noise reduced video signal, otherwise. - View Dependent Claims (9, 10, 11, 12, 13, 14)
-
Specification