Scott H Lewis

US Patent:

48537950, Aug 1, 1989

Filed:

Jul 24, 1987

Appl. No.:

7/077530

Inventors:

Roger R. A. Morton - Rochester NY
Scott Lewis - Ann Arbor MI

Assignee:

Eastman Kodak Company - Rochester NJ

International Classification:

H04K 140

US Classification:

358447

Abstract:

Apparatus, and an accompanying method, for use in an image enhancement system for providing background and noise values which, in many instances, are more representative of background and noise levels occurring in a scanned video image than those values previously obtainable in the art. This apparatus, which in its general form can be used to implement both a noise tracking circuit and/or a background tracking circuit, includes a two-dimensional non-linear, preferably infinite impulse response, filter that provides an output filtered value based upon the value of an incoming pixel situated on a current scan line and to first and second prior output values. The first prior output value is the output filtered value that is associated with a pixel located on a pre-determined one of a plurality of prior scan lines and situated to the right of the current pixel. The second prior output value is the output filtered value that is associated with a pre-selected pixel situated on the current scan line and located to the left of said current pixel.

US Patent:

49822942, Jan 1, 1991

Filed:

Jul 24, 1987

Appl. No.:

7/077529

Inventors:

Roger R. A. Morton - Rochester NY
John E. Redden - Rochester NY
Scott Lewis - Ann Arbor MI

Assignee:

Eastman Kodak Company - Rochester NY

International Classification:

H04N 140

US Classification:

358465

Abstract:

Apparatus for enhancing and thresholding scanned microfilm images, specifically for removing single pixel noise therefrom, and accompanying methods for use therein are disclosed. Specifically, this apparatus convolves each one of a pre-defined group of incoming pixel values with a corresponding one of a pre-defined set of coefficients in order to generate an convolved pixel value. The convolved pixel is then compared against a threshold level to produce a thresholded pixel value indicative of the results of the comparison. The inventive apparatus also includes a noise processing circuit that contains a noise tracker and a noise detector and filter circuit. The noise tracker is used to produce a noise value that tracks a noise level present in the threshold pixel value. The noise detector and filter circuit filters pixel noise from the thresholded pixel value and, in response thereto, produces a corresponding output pixel value for a current incoming pixel value being processed and provides a signal to the noise tracker that pixel noise has been detected. A background tracker, which also forms part of the inventive apparatus, produces a background value that tracks a background level present in the incoming pixel values.