Interlaced video is a technique used to double the perceived frame rate of a video source without consuming extra bandwidth. Rather than increasing the total frame rate by two, interlacing instead alternates which lines of the display are refreshed in each pass creating the illusion of a higher refresh rate.
Interlaced video is favored by broadcasters and content distributors because it allows them to transmit twice the the display refresh rate using half the bandwidth of a progressive video (which refreshes every line of the display instead of every other line). Action movies, sports broadcasts, and other motion-filled video benefit from a higher refresh rate as it creates the illusion of smoother motion with less overhead on the delivery and display system.
It is quite possible interlaced video will disappear in the future as available bandwidth increases and broadcasters are no longer forced to strike a balance between the refresh rate and volume of data streamed to the viewing device. For a more in-depth look at the difference between progressive and interlaced video scanning, check out What Is the Difference Between 1080p and 1080i?
- By Jason Fitzpatrick on 02/24/13