Kwok Har Lam

US Patent:

49185349, Apr 17, 1990

Filed:

Apr 22, 1988

Appl. No.:

7/184791

Inventors:

Kwok L. Lam - Chicago IL
Kunio Doi - Willowbrook IL
Kenichi Komatsu - Tochigi, JP
Michitaka Honda - Tochigi, JP

Assignee:

The University of Chicago - Chicago IL
Kabushiki Kaisha Toshiba - Kawasaki

International Classification:

H04N 315
H04N 718

US Classification:

358225

Abstract:

An optical image processing method and system in a radiographic system, wherein an image of an object is produced by an image intensifier and converted to video signal by a television (TV) camera system. A liquid crystal display (LCD) is placed bewteen the image intensifier and the T. V. camera system at a location shifted from a focal plane of the T. V. camera system. The liquid crystal display defines plural pixels which are controllable so that light produced by the image intensifier and impinging on the plural LCD pixels can be selectively attenuated by application of selected control signals to the LCD. Control signals are generated selectively based on predetermined parameters of the radiographic system and the image. These control signals are applied to the LCD to perform selective attenuation and corresponding dynamic range compression of light passing through respective LCD pixels, thereby to perform unsharp masking of the image produced by the image intensifier using the LCD.