Motion detector for TV picture noise reduction system - has low pass filter, and band-pass filter with response corresp. to visual acuity

摘要

The motion detector comprises a digital temporal filter (1) which combines the picture sample to be processed (E) with the corresp. sample from a memory (2) in accordance with the output of a threshold decision circuit (5). The same two samples are subtracted for division between two channels comprising a low-pass digital filter (8) and a band-pass filter (7) followed by a controllable polarity inverter (9). The two channel outputs are added to produce a filtered picture difference signal for the threshold decision circuit (5).. Detection errors in areas of fine detail leading to loss of definition are compensated. The complete system of noise reduction is less dependent on signal/noise ratio of the picture.