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:
Jan. 02, 1990
Filed:
Dec. 21, 1987
Katsuo Nakazato, Tokyo, JP;
Toshiharu Kurosawa, Yokohama, JP;
Yuji Maruyama, Tokyo, JP;
Kiyoshi Takahashi, Kawasaki, JP;
Hiroyoshi Tsuchiya, Kawasaki, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An image signal processing circuit for converting step-gradation density values (I.sub.xy) of successive picture elements to bi-level values (P.sub.xy) for display by a bi-level display device, in which a bi-level error (E.sub.xy) between a bi-level value determined for a picture element and an appropriate density value for the element is apportioned among a set of peripherally adjacent picture elements (A to D) by computing a corresponding set of error apportionment values (G.sub.A to G.sub.D), and in which a difference between the sum total of these apportionment values and the bi-level error is derived, and error apportionment is modified such as to eliminate the effects of this difference. Improved reproduction is thereby attained of image regions which are of uniformly high density or low density.