Television – Image signal processing circuitry specific to television – Gray scale transformation
Patent
1992-06-15
1995-05-16
Groody, James J.
Television
Image signal processing circuitry specific to television
Gray scale transformation
348692, 348652, H04N 516, H04N 972
Patent
active
054165334
ABSTRACT:
A pedestal clamping device clamps a pedestal level of an input video signal in response to a predetermined pedestal voltage, and converts the input video signal into a clamped video signal. A black-level expanding device expands a tone of a black portion of the clamped video signal, and converts the clamped video signal into a black-level expanded video signal. A color greatest detecting device detects a greatest of color signals of the input video signal. A adding device adds an output signal from the color greatest detecting device and the pedestal voltage. A black-level comparing device detects a blackest portion of the black-level expanded video signal; compares the detected blackest portion of the black-level expanded video signal with the output signal from the adding device; and controls a degree of expanding the black tone by the black-level expanding device in response to a difference between the detected blackest portion of the black-level expanded video signal and the output signal from the adding device.
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IEEE Transactions on Consumer Electronics, vol. 36, Aug. 1990, No. 3, pp. 699-706, New York, US., Imaizumi & Al.: "Development of Multifonctional NTSC System Signal-Chip LSI for Higher Picture and Sound Quality".
Groody James J.
Hsia Sherrie
Matsushita Electric - Industrial Co., Ltd.
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