Electronic noise reducing apparatus and method

Apparatus for reducing noise on an input electronic signal which noise has a peak to peak amplitude which is less than the peak to peak amplitude of said input electronic signal, to a level lower than that at the input of said noise reducing apparatus, with said apparatus requiring no special processing of said input electronic signal before noise is added, including in combination delay means for delaying said input electronic signal to provide a delayed input signal, comparison means for comparing said delayed input signal to said input electronic signal to determine the difference thereof and comparing said difference to a reference which may allow the larger of said reference or said difference to always be determined, and processing means responsive to said comparison means and the full amplitude of said delayed input signal to select as the output signal either an average of said input electronic signal and said delayed signal if said difference is less than said reference or said delayed signal otherwise which selection is in response to said comparison means.

Apparatus for generating a noise reduced version of an input electronic signal which has been derived by scanning a spatial image, including in combination delay means for delaying the output signal which is output from said apparatus which output signal represents a noise reduced version of the electronic signal previously input to said apparatus, comparison means for comparing at least one element of said input electronic signal to at least one element of said delayed output signal to determine the difference in said input and said delayed output signal elements and to perform a threshold comparison to determine if said difference is greater than a threshold, said elements corresponding to different points on the scanned image, and processing means responsive to said difference and said threshold comparison of said comparison means and at least one element of said output signal which has been delayed to generate said output signal which represents an average of said input electronic signal and said delayed output signal when said difference is less than said threshold and with said output signal being equivalent to said input electronic signal otherwise.

Apparatus for removing noise from an input video signal which is a color television video signal, including in combination, delay means for delaying said input video signal to provide a delayed input video signal corresponding to a point on the raster different from said input video signal, comparison means responsive to said delayed input video signal and said input video signal to determine the difference thereof for all signal conditions and comparing said difference to a reference to determine if said difference is less than said reference, and processing means responsive to said comparison means to construct a noise reduced version of said input video signal which version is an average of said input and delayed input video signals if said difference is less than said reference with said processing means responsive to said delayed input video signal and said comparison means to output said delayed input video signal if said difference is not less than said reference.

The method of removing noise on an input color television signal including the steps of delaying said input video signal to provide a delayed input video signal corresponding to a point in the raster different from said input video signal, comparing the delayed input video signal to the input video signal in its undelayed condition to determine the difference thereof under all signal conditions and to compare said difference to a reference to determine the larger thereof and processing the delayed input video signal and said difference in direct response to the aforementioned comparison to said reference to produce an output signal which is either an average of said input and delayed input video signal when said difference is less than said reference, or is equal to said input video signal.

The method of generating a noise reduced version of an input electronic signal including the steps of delaying said input electronic signal to produce a delayed input signal having the same bandwidth as said input electronic signal, comparing said input electronic signal to said delayed input signal to determine the difference thereof and comparing said difference to a reference which may allow the larger of said difference or said reference to always be determined, and processing said delayed input signal in response to said comparisons to generate a signal which may be changed from an average of said input and delayed input electronic signals to a signal equivalent to said input electronic signal in response to said comparisons.

The method of generating an output electronic signal which is a noise reduced version of an input electronic signal which has been derived by scanning a spatial image, including the steps of delaying said output electronic signal, comparing at least one element of said delayed output electronic signal to at least one element of said input electronic signal to determine the difference to said elements and comparing said difference to a reference to determine the larger thereof, said elements corresponding to different points on the scanned image, and processing said delayed output electronic signal with said difference in direct response to the aforementioned comparison of said difference and said reference to generate said output signal which is an average of said delayed output and input electronic signals when said difference is less than said reference or is equivalent to said input signal otherwise.