1. A system for detecting a periodic pattern in a video signal, the system comprising: a pixel sampling module configured to define a horizontal sampling window and a vertical sampling window in at least one of a plurality of blocks defined by partitioning a video frame of a video signal, the horizontal and vertical sampling windows configured to sample a set of pixel values; a signal processor configured to: calculate a fast Fourier transform (FFT) of the pixel values in the horizontal sampling window, the FFT of the pixel values forming a horizontal frequency spectrum, and calculate an FFT of the pixel values in the vertical sampling window, the FFT of the pixel values forming a vertical frequency spectrum; and a spectrum analyzer configured to: compute a horizontal power spectrum from the horizontal frequency spectrum and a vertical power spectrum from the vertical frequency spectrum, and analyze the horizontal and vertical power spectrums for the presence of a peak, wherein the presence of a peak within the horizontal or the vertical power spectrums indicates the presence of a periodic pattern in the video frame.