| 摘要 |
<p>Method and apparatus for the conversion to and from digital form of a PAL colour television signal is described in which the digital signals represent the error between a particular sampled value of the signal and a predicted value for that particular sample, the predicted value being based on a previously occurring sampled value together with the difference between two similarly spaced sampled values occurring in the preceding line, the spacing of the two pairs of sampled values in the two lines being such that the phase change of the sub-carrier, if unmodulated, is the same in both cases. A simple switch delay system is described for effecting the selection of the sampling instants in the preceding line.</p> |
