Noise (video) 3338992 206287864 2008-04-17T17:38:25Z 85.231.106.7 Captialized to titles [[Image:TV noise.jpg|thumb|250px|right|On an empty channel, an analog TV receiver shows a "snowy" noise pattern.]] '''Noise''' in analog [[video]] and [[television]] is perceived as a random dot pattern which is superimposed on the picture as a result of [[electronic noise]] and radiated electromagnetic noise picked up by the receiver's [[antenna (radio)|antenna]] &ndash; it is the "[[White noise|snow]]" which is seen with poor analog television reception or on [[VHS]] tapes. When there is no transmission, which is to say no signal, the noise or "snow" is due mostly to [[Johnson-Nyquist noise|thermal noise]] from the device itself, stray electromagnetic fields from other household electric devices, and remnants of the microwave [[cosmic background radiation]] from the [[Big Bang]]<ref>[http://press.princeton.edu/chapters/s7481.html Sample Chapter for Lemonick, M.D.: Echo of the Big Bang<!-- Bot generated title -->]</ref>, all of which is interpreted as [[luma (video)|luminance signal]]. Approximately one-third to one-quarter of such static is residual background radiation from the birth of the cosmos.<ref>[http://www.turnoffyourtv.com/commentary/static.html KYTV - TV Static<!-- Bot generated title -->]</ref> Due to the algorithmic functioning of a [[digital television]] set's electronic circuitry and the inherent quantization of its screen, the "snow" seen on digital TV is less random, and being almost entirely a product of its own electronics, no cosmic background radiation is displayed.<ref>[http://www.wonderquest.com/fast-answers.htm WonderQuest: Fast answers<!-- Bot generated title -->]</ref> UK viewers see "snow" on black after sign-off, instead of "bugs" on white, a purely technical artifact due to British receivers using positive rather than the negative video modulation used in Canada and the U.S. Since one impression of the "snow" is of fast-flickering black bugs on a cool white background, in [[Sweden]] the phenomenon is often called ''Myrornas Krig'', "War of the Ants".{{Fact|date=February 2008}} ==References== {{reflist|1}} ==See also== *[[Noise (radio)]] *[[Interference]] [[Category:Noise|Video]] {{tech-stub}} [[nl:Ruis (televisie)]] [[ja:スノーノイズ]] [[sv:Myrornas krig]]