Patent ID: 6239772
Filing Date: 2001-05-29
Classification: H04N

Abstract:
A method of reducing a moire phenomenon upon display of a video signal (VI) on a display device (CRT), comprising the step of filtering (NF) for obtaining a passband substantially corresponding to a baseband portion of said video (VI), characterized in that the step of filtering (NF) is adapted for obtaining a notch in an amplitude characteristic:a) at or near to a spatial frequency of dots (fdh; fhh) on a display screen (DS) of the display device (CRT), orb) at or near to a spatial higher harmonic (f2h, f4h) of the baseband video (f1h), which spatial higher harmonic (f2h, f4h) is near to a spatial frequency of the dots (fdh; fhh) on the display screen (DS),and wherein the step of filtering further comprises controlling a notch frequency by a signal from a resolution detector.