| 摘要 |
<p>PURPOSE:To detect a fast moving signal by switching a band characteristic of a band pass filter to eliminate a color component from the output of a subtractor detecting the moving signal of brightness and making the sand of an input video signal without vertical correlation narrow. CONSTITUTION:Outputs of low pass filters (LPF) 112, 113 are switched by an output of a comparator circuit 118 at a changeover switch 114. That is, when the color component is detected, the signal passes through the IPF 113 and when no color component is detected, the signal passes through only the LPF 112. Thus, after a difference between lines of a current field, i.e., a line difference of a luminance signal and a chrominance signal is detected by a subtractor 115, only the color component is extracted by a BPF and a signal processed into an absolute value by an absolute value circuit 117 is converted into a signal of '1', '0' with an external comparison level. Then outputs of the LPFs 112, 113 are selected by the changeover switch 114 and the selected signal is outputted. Thus, no erroneous moving signal is generated and a luminance moving signal with fidelity to a fast moving signal is extracted.</p> |
