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. 24, 1989
Filed:
Aug. 14, 1987
Regis J Crinon, Beaverton, OR (US);
Yih-Chyun Jenq, Lake Oswego, OR (US);
Tektronix, Inc., Beaverton, OR (US);
Abstract
A two-dimensional array of binary values is used to control operation of a bi-level imaging device. The array of binary values is formed by applying an enhanced array g(u,v) to a two-dimensional array of threshold values. A two-dimensional array of pixel value f(u,v) is used to form the enhanced array g(u,v) such that g(u,v)=m.sub.f +k[f(u,v)-m.sub.f ] where m.sub.f is the average value of f(u+a, v+b) from a=-L to a=+L and b=-M to b=+M and k is a gain function which depends on the standard deviation in f(u+c, v+d) from c=-N to c=+N and d=-P to d=+P. L, M, N and P define the sub-array over which the standard deviation is calculated. Preferably, L, M, N and P are each equal to 2. The value of k is a decreasing function of the standard deviation: the larger the standard deviation, the smaller the gain factor k. The rate at which k decreases with increase in the standard deviation depends on the edge sampling characteristics of the array of threshold values.