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. 07, 1993
Filed:
Jan. 28, 1991
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06K / ;
U.S. Cl.
CPC ...
382 53 ; 382 50 ; 358465 ; 358466 ;
Abstract
A method and apparatus for binarizing a variable density image wherein brightness of the variable density image is changed by 1/n (where n is an integer of 2 or above), and an expansion processing is carried out on the brightness changed image to generate an expanded image. A smoothing processing is performed on the expanded image to generate a smoothed image and a differential image is generated by taking a difference between the smoothed image and the variable density image. The differential image is binarized by comparing the differential image to a predetermined threshold.