Editing Subcarrier (section)

==Television==
Likewise, analog [[television|TV]] signals are transmitted with the [[monochrome|black and white]] [[luminance (video)|luminance]] part as the main signal, and the color [[chrominance]] as the subcarriers.  A black and white TV simply ignores the extra information, as it has no decoder for it.  To reduce the bandwidth of the color subcarriers, they are filtered to remove higher frequencies.  This is made possible by the fact that the [[human eye]] sees much more detail in [[contrast (vision)|contrast]] than in color.  In addition, only blue and red are transmitted, with green being determined by subtracting the other two from the luminance and taking the [[remainder]]. (See: [[YIQ]], [[YCbCr]], [[YPbPr]])  Various [[broadcast television system]]s use different subcarrier frequencies, in addition to differences in [[video encoder|encoding]].

For the audio part, [[Multichannel television sound|MTS]] uses subcarriers on the video that can also carry three audio channels, including one for stereo (same left-minus-right method as for FM), another for [[second audio program]]s (such as [[descriptive video service]] for the vision-impaired, and bilingual programs), and yet a third hidden one for the studio to communicate with reporters or technicians in the field (or for a [[technician]] or [[broadcast engineer]] at a remote [[transmitter]] site to talk back to the studio), or any other use a [[TV station]] might see fit. (See also [[NICAM]], [[A2 Stereo]].)

In RF-transmitted [[composite video]], subcarriers remain in the baseband signal after main carrier [[demodulation]] to be separated in the receiver.  The mono audio component of the transmitted signal is in a separate carrier and not integral to the video component.  In wired video connections, [[composite video]] retains the integrated subcarrier signal structure found in the transmitted baseband signal, while [[S-Video]] places the chrominance and luminance signals on separate wires to eliminate subcarrier crosstalk and enhance the signal bandwidth and strength (picture [[Acutance#Sharpness|sharpness]] and brightness).