| 摘要 |
PURPOSE:To improve the picture quality in vertical edge parts by stopping supply of an inter-field difference signal to a maximum value circuit at the time when the maximum value of one or more inter-frame difference signals outputted from an inter-frame difference signal generating circuit is larger than a prescribed value. CONSTITUTION:The video signal inputted from an input terminal 1 is delayed by one frame through a 1H delay circuit 20, a 262H delay circuit 21, and a 262 delay circuit 22, and the inter-frame difference signal is obtained from a subtracting circuit 25. When the inter-frame difference signal is smaller than the prescribed value, that is, when the video signal inputted to the terminal 1 is a still picture, a switch 30 is turned on. Then, the inter-field difference signal outputted from an absolute value circuit 27 is given to a maximum value circuit 29. With respect to a still picture, a maximum value of the difference signal between scanning lines 33 and 31 and that between lines 32 and 33 is obtained, and vertical edges are surely detected even in high band components of 525/4cph or higher. With respect to a moving picture, the switch 30 is turned off, and the inter-line difference signal appears in an output terminal 13, and vertical edges cannot be detected. |
