| 摘要 |
<p>PURPOSE:To make easy the band compression, by doubling the sampled frequency for that of the band compression, in coding the NTSC system color television signal. CONSTITUTION:The sampled frequency suitable for the band compression by low bit rate required for transmission is selected to 2fsc+ or -1/4 fh. Where fsc is color sub- carrier frequency and fh is horizontal scanning frequency, and this sampled frequency eliminates the duplication at folding for the luminance signal spectrum and the chroma signal spectrum. The input signal via LPF 1 is picked up for fsc with the 4 fsc generator 31 and the fh component with the 1/2 fh generator 32, and the frequency of 4(fsc+ or -1/8 fh) is generated from the sampled frequency generator 3, and the input signal is sampled and coded with the coder 2. In the transmission, the signal of a given rate can be obtained by sampling every other output signal.</p> |
