VIDEO LUMINANCE CHROMINANCE SEPARATION

摘要

The invention provides techniques for separating luma and chroma signal components in a composite SECAM video signal. During reception, the SECAM video signal is split into luma and chroma output. The amplitude of the chroma carrier is monitored during reception. If the chroma carrier amplitude is greater than a threshold, the value of the chroma output can be reduced. Also, if the chroma carrier amplitude is greater than another threshold, a portion of the chroma carrier can be added to the luma; or the trap band of the band-trap filter for extracting luma from the composite video can be reduced. The respective amount of the reduction in the chroma output and the increase in the luma output are independently determined but both may proportional to the magnitude of the deviation in the chroma carrier amplitude from the different thresholds.