Signal quality monitoring system
 A cable television signal for example may be monitored and impairments determined and in many cases classified by grabbing at least portion of a transmitted frame of video information somewhere on the network to provide a video signal, performing a two dimensional Fourier transform on the video signal and analyzing the Fourier transform so obtained to determine the location of areas indicating above average occurrence of specific frequencies to provide an indication of an impairment. 
The University of British Columbia
H G G H
H04N G01R G01R H04N
inventional inventional inventional inventional
Rabab K. Qin
Ward Zhang