| 摘要 |
<p>PURPOSE:To accurately take out a motion signal being promptly moved when a chrominance signal does not exist, to narrow the band of an LPF and to completely eliminate the chrominance signal when the chrominance signal is intense by detecting the level of a chrominance signal, and making variable the band of the LPF to fetch a luminance differential signal from a one frame differential signal. CONSTITUTION:An input signal 101 is a video signal in an NTSC system, and digitized by an A/D converter. A DELTAY signal to be a frame differential luminance signal and the double chrominance signal (the added chrominance signals at the present frame and the following frame) are produced as the output of a subtracter 103 to detect the differential signal between the both edges delayed by one frame, the chrominance signal is eliminated by the LPF, and only the DELTAY signal is fetched. LPFs 104, 105 and 106 are the filters in the narrower band than the LPF connected to the same band or the preceding band, and coefficient multipliers 107, 108 and 109 gain-control the output of the LPFs 104, 105 and 106 by the output of a coefficient generating circuit 113. The chrominance signal is separated by an inter-line YC separator circuit 111, made into an absolute value by an absolute value circuit 112, and the gain of the coefficient multiplier is controlled by the size of the output.</p> |
