Automatic recognition of intermodulation beat products in cable television pictures

It was found previously (Ward and Zhang 1992) that the two-dimensional Fourier transform of a picture impaired by intermodulation beat products contains distinguishable pulses. Each product results in four pulses with special characteristics. The authors further analyze and study the intrinsic properties of these pulses. Based on these properties a method is designed which can detect these pulses, even if the picture is also impaired by snow as long as the intermodulation impairment is visible to the human eyes