| 摘要 |
PURPOSE:To reduce the occurrence of dot interference, by using a band-pass filter for horizontal chrominance components at the time of ordinary luminance signal-chrominance signal separation and a band-pass filter for vertical chrominance signal when input pictures strongly change. CONSTITUTION:Sample values at three sampling points are simultaneously obtained by delaying composite video signals 101 and luminance signal- chrominance signal separating filter is formed based on the sample values. When a picture which is not suitable for signal separation is detected at a horizontal chrominance signal band-pass filter 6c, the signal separation is performed at a vertical chrominance signal band-pass filter 6d. Namely, a selection circuit 9 inputs signals 107 and 111 as control signals and outputs either one of the output signal 113 of the filter 6d and output signal 115 of the filter 6c as chrominance signal 116. Morever, a subtraction circuit 10a subtracts the signal 116 from composite signals 117 and outputs luminance signals 118. Therefore, leakage between luminance signals and chrominance signal can be reduced and the occurrence of dot interference can be reduced.
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