Joseph Shu

US Patent:

49262670, May 15, 1990

Filed:

May 26, 1989

Appl. No.:

7/358061

Inventors:

Joseph S. Shu - White Plains NY
Robert Springer - Wyckoff NJ
Chia L. Yeh - Saratoga CA

Assignee:

Nynex Corporation - New York NY

International Classification:

H04N 140

US Classification:

358454

Abstract:

A method and system for reproducing halftone originals utilizing threshold gray level values of the scanned pixels of the halftone original to determine adjacent pairs of pixels bordering the edges of the halftone dots. Edge errors for the adjacent pairs of pixels are determined using the scanned gray level values and a threshold value. A processing window defines sub-arrays of pixels whose thresholded gray level values are processed based on the edge errors. For each sub-array, the edge errors of the adjacent pairs of pixels are summed. The thresholded values of the adjacent pairs of pixels are then selectively changed in the order of pixel pairs of descending edge error until the number of values changed equals the closest integer to the summed edge error.

US Patent:

49424807, Jul 17, 1990

Filed:

Sep 6, 1988

Appl. No.:

7/241073

Inventors:

Joseph S. Shu - White Plains NY

Assignee:

Nynex Corporation - White Plains NY

International Classification:

H04N 140

US Classification:

358455

Abstract:

Reproduction of an original containing screened artwork is accomplished by selecting the scanning frequency to have a predetermined relationship to the screen frequency of the artwork and by utilizing adaptive thresholding methodology to convert the scanned digital signals to processed binary signals which are such as to result in the average gray levels over corresponding arrays of binary signals and digital signals being approximately equal.

US Patent:

49840975, Jan 8, 1991

Filed:

Jan 31, 1989

Appl. No.:

7/304428

Inventors:

Joseph S. Shu - White Plains NY

Assignee:

Nynex Corporation - New York NY

International Classification:

H04N 140

US Classification:

358429

Abstract:

A practice for producing a halftone reproduction wherein a predetermined screen function is used to process the gray levels of the scanned original and wherein the halftone reproduction is made capable of exhibiting gray levels over the entire gray tone range of 0 (black) to 255 (white) by selecting the screen frequency in the screen direction so as to result in a screen frequency in the print direction which is other than a sub-multiple of the print frequency.