Processing of signals for interlaced display

摘要

Conversion of a computer graphics signal into an interlaced TV video signal using conventional signal processing can give rise to considerable flicker in the resulting display where there are highly contrasting odd and even fields. With the inventive signal processing means the output for each line of the video signal is created by summing a reduced intensity version of the current field and the filtered versions of the immediately adjacent field lines. The effect of applying the filter of a preferred processing means to a single pixel signal in line n is shown in the filter characteristic of the figure, the filter comprising a low-pass filter means which derives a low frequency Fourier component of the adjacent field lines that represents their brightness but not the fine details. This enables fine details to be preserved whilst substantially reducing flicker in the display.