Dot crawl
![Enlarged detail from a video source exhibiting dot crawl. Note the distinctive checkerboard pattern on the vertical edges between yellow and blue areas.](/Images/godic/202501/09/Crawl2248.jpg")
Dot crawl is the popular name for a visual defect of color analog video standards when signals are transmitted as composite video, as in terrestrial broadcast television. It consists of animated checkerboard patterns which appear along horizontal color transitions (vertical edges). It results from intermodulation or crosstalk between chrominance and luminance components of the signal, which are imperfectly multiplexed in the frequency domain.