cdtv_admin@cdtv.ca
07/29/2004
3:27 PM
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Jeffalan@shaw.ca wrote on 2004/17/2004
One of the benefits of high def tv will be having a much greater color range, and this could be
over 16 million colors. That is good but I have never even noticed that there was a limited color
range is the standard NTSC system? Can anyone explain how the color works in the NTSC system?
Jeff.
Reply from Admin.
In the NTSC color system, the signal is transmitted as a luminance signal (Y) and two color difference signals, (I, Q). These signals are carried on a sub-carrier at 3.58 Mhz interleaved into the luminance spectrum. To minimize cross-talk with the luminance, the color difference signals are severely band limited, making the color information of very low resolution. Even so, there are still many artifacts in the NTSC picture, such as crawling dots along sharp edges and striped shirts creating false colors, in addition to the poor resolution and high noise level due to analog transmission and to interference.
HDTV transmits a luminance signal (an improved Y signal with enhanced black detail) and two color difference signals (Pr and Pb). These signals are of relatively wide bandwidth (each half the luminance bandwidth) and take advantage of the enhanced black detail available to offer much improved picture performance in contrast, detail and color. The HDTV signals are transmitted digitally, avoiding the noise and interference problems of analog NTSC, but introducing some possible new artifacts in certain high-detail pictures due to the digital compression. In most scenes, the received HDTV picture is very close to the quality seen on the studio monitor, making for stunning results on the wide screen.
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