The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 11, 2001
Filed:
Dec. 11, 1998
Applicant:
Inventor:
Koji Urasawa, Tokyo, JP;
Assignee:
Oki Data Corporation, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
H04N 1/405 ; H04N 1/407 ;
U.S. Cl.
CPC ...
H04N 1/405 ; H04N 1/407 ;
Abstract
A continuous-tone image is converted to a bi-level image by first applying an inverse gamma correction to a threshold matrix, then comparing the gray levels in the continuous-tone image with the corrected threshold values. The threshold matrix may be selected from a library of threshold matrices, and the inverse gamma correction applied by using a gamma correction table selected from a library of such tables. Alternatively, a library containing at least one corrected threshold matrix, to which the inverse gamma correction has already been applied, may be stored.