Video noise reduction system employing plural frequency bands
AssigneeThomson Consumer Electronics, Inc.
InventorTodd J. Christopher
Life of this patent
Estimating the term…
Abstract
An input filter separates a luminance input signal into a high frequency component that is noise reduced by coring and a low frequency component that is noise reduced by a frame recursive filter preceded by sub-sampling and followed by sample rate restoration by interpolation. An output circuit combines the noise reduced components to provide a processed output signal in which high frequency portions thereof are subjected to coring and low frequency portions thereof are subjected to recursive filtering. In a specific application the frame recursive filter provides a plurality of low frequency sub-sampled components which are combined with the processed output signal in a further output circuit to provide a noise reduced output signal of progressive scan form.
Claims17
Video noise reduction apparatus, comprising:
- a source for providing a digital video input signal having a given sampling rate;
- an input signal processor coupled to said source for separating said video input signal into a high frequency component of said given sample rate and a sub-sampled low frequency component having a lower sample rate;
- a frame recursive filter coupled to said input processor for frame recursively filtering sub-sampled low frequency component;
- and
- an output processor for coring said high frequency component, for restoring the sample rate of said frame recursively filtered low frequency component and for combining the resultant low and high frequency components to form a noise reduced digital video output signal.
A video noise reduction system, comprising:
- an input filter for separating an input signal supplied thereto via a source into low and high frequency components;
- a signal combiner;
- a first path including means for inhibiting low amplitude signal levels of said high frequency component and for coupling said high frequency component to a first input of said combiner;
- a second path including a recursive filter for coupling said low frequency component to a second input of said combiner.
Video noise reduction apparatus, comprising:
- a source for providing a video input signal;
- an input processor coupled to said source for dividing said video input signal into a low frequency component and a high frequency component;
- a first filter coupled to said input processor for frame recursively filtering said low frequency component;
- a second filter coupled to said input processor for coring said high frequency component;
- and
- an output processor for combining said cored high frequency component with said frame recursively filtered low frequency component to provide a resultant noise reduced video output signal.
Dependencies are inferred from the claim text.