Facsimile and static presentation processing – Facsimile – Specific signal processing circuitry
Patent
1979-01-11
1980-10-28
Safourek, Benedict V.
Facsimile and static presentation processing
Facsimile
Specific signal processing circuitry
358169, H04N 514
Patent
active
042310652
ABSTRACT:
A local area contrast enhancement scheme for a video display includes a two dimensional recursive filter to obtain a moving average of the intensity variations in all areas of the display. This moving average is subtracted from the original signal to produce a signal which contains only local variations and this latter signal is expanded to increase the display contrast. The local area contrast enhancement scheme allows low contrast details to be perceived and permits hands-off operation of the display under varying scene conditions. The recursive filter approach results in a simple implementation of the enhancement scheme with both analog and digital circuitry.
REFERENCES:
patent: 3181007 (1965-04-01), Hinds
patent: 3600506 (1971-08-01), Richeson, Jr.
patent: 3751586 (1973-08-01), Johansson
patent: 3786183 (1974-01-01), Satterfield
patent: 3790706 (1974-02-01), Gubala et al.
patent: 3898379 (1975-08-01), Howe et al.
patent: 3952144 (1976-04-01), Kolker
patent: 3996421 (1976-12-01), Pruznick et al.
patent: 4057828 (1977-11-01), Monahan
patent: 4081836 (1978-03-01), Skinner
Publication entitled "Image Enhancement Techniques for Cockpit Displays", an unclassified report on DD form 1473 submitted by Ketcham, Lowe and Weber of the Hughes Aircraft Company to the Navy and bearing the catalog No. AD-A008 458 and indicating the report date being Dec. 1974.
A paper entitled "Real-Time Image Enhancement Techniques" by David J. Ketcham of the Hughes Aircraft Company and appearing in SPIE/OSA vol. 74 (1976) on pp. 120-125.
An article entitled "Constant Variance Enhancement: A _Digital Processing Technique" authored by James L. Harris, Sr. and found on pp. 1268-1271 of vol. 1, No. 5/May 1977 issue of Applied Optics.
Fitch Robert C.
Narendra Patrenahalli M.
Honeywell Inc.
Safourek Benedict V.
Ungemach Charles J.
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