What is Comb Filter, 2-line Digital?

Comb Filter, 2-line Digital — The 2-line digital comb filter employs digital circuitry to electronically separate the colour from the black and white in a composite video television signal. The filter compares adjacent scan lines to determine which pair of lines is the most similar (or correlated). Using this correlation, the advanced digital comb filter can minimize dot crawl and cross-colour interference.