What does interlacing mean?

CRT televisions and monitors display images using horizontal lines called scanlines, in the past most cameras shot videos with these lines.

Interlacing divides a video frame into two alternating fields, displaying either the odd or even lines of the image. By presenting each field sequentially, interlacing aims to enhance motion portrayal and minimize flickering in video displays.

History

Interlacing was once a common technique in analog television systems and early digital video formats, alternating between odd and even image lines to reduce flicker. However, modern digital video standards like progressive scan, which includes every line in each frame, have largely supplanted interlacing across many applications. This shift is due to progressive scanning's higher image quality and synergy with contemporary display technologies.