Television – Image signal processing circuitry specific to television – Noise or undesired signal reduction
Patent
1994-03-22
1995-08-15
Groody, James J.
Television
Image signal processing circuitry specific to television
Noise or undesired signal reduction
348616, 348416, 348420, H04N 5213
Patent
active
054424070
ABSTRACT:
A video signal noise reduction system is disclosed in which corresponding image pixels from a current frame and image pixels from a noise reduced previous frame are averaged to produce respective noise reduced pixel values. In the disclosed exemplary embodiment of the invention, a processed frame memory stores a noise reduced image and a motion estimator identifies a target block of pixels in this processed frame memory to be used in calculating a noise reduced video signal. A motion compensated noise reduction processor combines the block of the noise reduced image pixels stored in the processed frame memory with a current block of pixels generated from the video signal to produce a motion block of noise reduced pixels. The relative weighting applied to the stored pixel and the current pixel depends on the number of pixels that were used to generate the stored pixel. A breakdown detector discards pixels in the motion block if a measure of noise reduction achieved for the one component divided by a measure of noise in the motion block is greater than a threshold value. Sparkle reduction is used to replace any original component of the motion block with its corresponding noise reduced component if all of the components adjacent to the original component have been replaced by their corresponding noise reduced components.
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Groody James J.
Matsushita Electric Corporation of America
Murrell Jeffrey S.
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