Editing Chroma subsampling (section)

===4:1:1===
In 4:1:1 chroma subsampling, the horizontal color resolution is quartered, and the bandwidth is halved compared to no chroma subsampling. Initially, 4:1:1 chroma subsampling of the [[DV (video format)|DV]] format was not considered to be broadcast quality and was only acceptable for low-end and consumer applications.<ref name="dv-betacam">{{cite web |url=http://www.dvcentral.org/DV-Beta.html |title=DV vs. Betacam SP |last=Jennings |first=Roger |author2=Bertel Schmitt |year=1997 |work=DV Central |access-date=2008-08-29 |archive-url=https://web.archive.org/web/20080702013821/http://www.dvcentral.org/DV-Beta.html |archive-date=2008-07-02 |url-status=dead}}</ref><ref name="dv-formats">{{cite web |url=http://www.adamwilt.com/DV-FAQ-tech.html |title=DV, DVCAM & DVCPRO Formats |last=Wilt |first=Adam J. |year=2006 |work=adamwilt.com |access-date=2008-08-29}}</ref> However, [[DV (video format)|DV]]-based formats (some of which use 4:1:1 chroma subsampling) have been used professionally in electronic news gathering and in playout servers. DV has also been sporadically used in feature films and in [[digital cinematography]].

In the [[480i]] "NTSC" system, if the luma is sampled at 13.5&nbsp;MHz, then this means that the '''Cr''' and '''Cb''' signals will each be sampled at 3.375&nbsp;MHz, which corresponds to a maximum [[Nyquist–Shannon sampling theorem|Nyquist]] bandwidth of 1.6875&nbsp;MHz, whereas traditional "high-end broadcast [[NTSC|analog NTSC]] encoder" would have a Nyquist bandwidth of 1.5&nbsp;MHz and 0.5&nbsp;MHz for the [[YIQ|I/Q]] channels. However, in most equipment, especially cheap TV sets and [[VHS]]/[[Betamax]] [[VCR]]s, the chroma channels have only the 0.5&nbsp;MHz bandwidth for both '''Cr''' and '''Cb''' (or equivalently for I/Q). Thus the DV system actually provides a superior color bandwidth compared to the best [[Composite video|composite analog]] specifications for NTSC, despite having only 1/4 of the chroma bandwidth of a "full" digital signal.

Formats that use 4:1:1 chroma subsampling include:
* [[DVCPRO]] / D-7 ([[NTSC]] and [[PAL]])
* [[480i]] "NTSC" [[DV (video format)|DV]] and [[DVCAM]]