| 摘要 |
<p>A video signal is sampled (2A) with a sampling frequency which is at least four times of the highest frequency of the video signal, subsequently, sampled signals are converted into digital signals (2B) and component thereof which are higher than the highest frequency of the video signal are eliminated by a low pass filter (3), then, remaining sampled signals are alternately decimated by a decimation circuit (4), thus the sampling frequency is reduced in appearance to the half thereof.</p> |
