Facsimile and static presentation processing – Static presentation processing – Attribute control
Patent
1991-12-26
1993-07-27
Peng, John K.
Facsimile and static presentation processing
Static presentation processing
Attribute control
358 27, H04N 978
Patent
active
052314782
ABSTRACT:
An apparatus and method for producing improved adaptive control signals for a luminance and chrominance separation circuit employing adaptive filtering of a chrominance signal includes a vertical difference detector, a horizontal difference detector, and a combiner. The vertical difference detector contains upper difference detector and lower difference detector, each of which receives a horizontally filtered next line signal (L.sub.N), a horizontally filtered present line signal (L.sub.P), and a horizontally filtered last line signal (L.sub.L), and which produce, respectively, an upper difference signal and a lower difference signal. In a preferred embodiment, the lower and upper difference detectors implement, respectively, the expressions .vertline.2L.sub.L +L.sub.P -L.sub.N .vertline. and .vertline.2L.sub.N +L.sub.P -L.sub.L .vertline.. The vertical detector also contains a larger valve selector that receives the upper and lower difference signals and produces a vertical chrominance difference signal that is based on, and preferably is the larger of the upper and lower difference signals. The horizontal difference detector receives the present line signal and determines the absolute value of the sum of the values of two pixels that are separated by an integral number of half cycles of a subcarrier frequency to produce a horizontal chrominance difference signal. The combiner contains a subtracter for subtracting the horizontal chrominance difference signal from the vertical chrominance difference signal to produce an adaptive control signal, and may further include a scaler on the subtracter input and a divide-by-two circuit and/or a limiter on the subtracter output.
REFERENCES:
patent: 4088080 (1987-08-01), Wagner
patent: 4703342 (1987-10-01), Takahashi
patent: 4920408 (1990-04-01), Umezawa
patent: 4933748 (1990-06-01), Katsuki et al.
patent: 4985757 (1991-01-01), Yasuki et al.
patent: 4992856 (1991-02-01), Robinson
patent: 4994906 (1991-02-01), Moriwake
patent: 5019895 (1991-05-01), Yamamoto
Gray Francis I.
Murrell Jeffrey S.
Peng John K.
Smith-Hill John
The Grass Valley Group Inc.
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