| 摘要 |
PURPOSE:To reduce cross-color and dot disturbances by separating the luminance signal and the chrominance signal after using a signal value series having a direction in which both wave-forms of vertical and horizontal directions of composite video signals make more gradual variations. CONSTITUTION:A sampling series 101 of NTSC system's composite color TV signals which is sampled by sampling frequencies fs=4fsc through a A/D converter 4 obtains simultaneously sampled values in five sampling points on a diamond type grid by passing through delay circuit 51, 52, 53 and 54. After seeking high energies of both vertical and horizontal directions in connection with signals S (m and n) of noticeable sampling points, its sampling series is compared with each other and changes over switch circuits 11 so that filter's outputs toward a direction having little high energies are selected. Then signals in a direction having less wave-forms are detected by using four vertical and horizontal sampling points which have phase differences of color sub-carrier waves by 180 deg. and separate the luminance and chrominance signals by using signals of the direction which has less wave-forms.
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