| 摘要 |
PURPOSE:To reduce a noise component in a digital signal and to calculate ghost information accurately by providing a noise eliminating circuit between a video signal A/D converting circuit and a ghost arithmetic circuit. CONSTITUTION:A signal passed through a transversal filter (TR)1 is subtracted from an input video signal to obtain a ghost-free output video signal. The leading edge of a vertical synchronizing signal is extracted 3 from the output composite video signal and its difference 4 from a slightly-delayed signal is calculated. This difference signal is converted by the A/D converting circuit 5 into a digital signal and is supplied to a noise eliminating circuit 8 to remove random noise by digital processing and to apply the resulting signal to the ghost arithmetic circuit 6. The amplitude of a ghost and a delay time are calculated on the basis of the noise-removed digital signal to change the tap gains at every stage of the TF1. |
