| 摘要 |
<p>PURPOSE: To perform an optimum contour correction by adopting a fuzzy theory, adjusting the brightness of a screen at a luminance level, controlling the fineness of the screen with a horizontal direction high-band component and a vertical direction correlation quantity of a luminance signal, and controlling a signal-to- noise ratio with an envelope of a video signal. CONSTITUTION: A reproduced composite video signal is applied to a luminance signal separator 1, separated into a luminance signal and a chroma signal, the luminance signal is clamped by a clamping circuit 2, and after integrated, applied to a luminance level amplifier 4A in a DC level amplification part 400. A high-pass filter 5, on the other hand, detects a high-band component determining the fineness of an image from the separated luminance signal and provides it to an amplifier 6. After an envelope of the video signal is detected by an envelope detector it is applied to an envelope level amplifier 4D and is converted into a pick level of an envelope direct current. Then the amplifiers 4A to 4D provide the respective luminance levels, the signal levels of the video envelope, etc., to a fuzzy microcomputer 16.</p> |
