Black level correction circuit for correcting black level of a v

Details Black level correction circuit for correcting black level of a v Black level correction circuit for correcting black level of a v

1988-05-16

1989-03-07

Groody, James J.

Facsimile and static presentation processing

Facsimile

Specific signal processing circuitry

358 34, 358172, H04N 516

Patent

active

048111015

ABSTRACT:
A black level correction circuit includes an extraction circuit for extracting a black signal from a video signal as a signal whose level is lower than a reference level, and a black level expanding circuit for expanding in level of the black signal for that peak level of the black signal equals a normal black level. The circuit further includes a level adjusting circuit which adjusts the reference level for extracting the black signal on the basis of at least one of an average value of a luminance signal portion the video signal, and a beam current value of a cathode-ray tube to which the video signal is supplied. With the variable reference level, contrast is improved for pictures having high luminance levels or low luminance levels on the whole.

REFERENCES:
patent: 2301522 (1942-11-01), Cawein
patent: 3309462 (1967-03-01), Loughlin
patent: 3927255 (1975-12-01), Yorkanis
patent: 3959811 (1976-05-01), Shanley, II
patent: 4110790 (1978-08-01), Wheeler
patent: 4631589 (1986-12-01), Hongu et al.
patent: 4660084 (1987-04-01), Fillman et al.
patent: 4660085 (1987-04-01), Harwood et al.
patent: 4730210 (1988-03-01), Leshko

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