In NTSC and PAL, hue is represented by a phase shift of the chrominance signal relative to the color burst, while saturation is determined by the amplitude of the subcarrier.
12.
SECAM is unique in not having a colorburst signal, since the chrominance signals are encoded using FM rather than QAM, thus the signal phase is immaterial and no reference point is needed.
13.
As S-Video maintains the two as separate signals, such detrimental low-pass filtering for luminance is unnecessary, although the chrominance signal still has limited bandwidth relative to component video.
14.
A monochrome signal is identical to a color one, with the exception that the elements shown in color in the diagram ( the color burst, and the chrominance signal ) are not present.
15.
Note that ghosts are a problem specific to the video portion of television, largely because it uses FM for the chrominance signal, hence ghosting only affects the luma ( video ) portion of its signal.
16.
In some analog color CRT displays, starting in 1956, the brightness control signal ( luminance ) is fed to the cathode connections of the electron guns, and the color difference signals ( chrominance signals ) are fed to the control grids connections.
17.
A gated and filtered signal derived from the color subcarrier, called the burst or colorburst, is added to the horizontal blanking interval of each line, excluding the vertical sync interval, as a synchronizing signal and amplitude reference for the chrominance signals.
18.
Their exact frequencies were chosen such that ( for NTSC ), they are midway between two harmonics of the frame repetition rate, thus ensuring that the majority of the power of the luminance signal does not overlap with the power of the chrominance signal.
19.
Physically, this chrominance signal is a 3.58 MHz ( NTSC ) or 4.43 MHz ( PAL ) sine wave which, in response to changing U and V values, changes phase as compared to the subcarrier, and also changes amplitude.
20.
Combining this reference phase signal derived from the color burst with the chrominance signal's amplitude and phase allows the recovery of the'I'and'Q'signals which when combined with the Luminance information allows the reconstruction of a color image on the screen.
