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:
Jul. 09, 2019
Filed:
May. 25, 2016
Hitachi Kokusai Electric Inc., Tokyo, JP;
Yoshiki Agata, Tokyo, JP;
Muneaki Yamaguchi, Tokyo, JP;
HITACHI KOKUSAI ELECTRIC INC., Tokyo, JP;
Abstract
In a method for determining upper and lower limit values for a target brightness when image contrast is extended, an upper and lower limit value search processing unit establishes two adjacent areas in accordance with brightness of a grayscale histogram, and, while scanning the positions of those areas, compares the frequency of those areas to a threshold, and if one frequency value is greater than or equal to the threshold value and the other frequency value is lower than the threshold, performs upper and lower limit value search processing wherein a brightness value at the boundary of the two areas is determined as an upper or lower limit value. Thresholds for upper and lower limit value search start position and frequency are established based on the shape of the grayscale histogram of an image to be processed. The shape of the grayscale histogram is identified according to preset classifications.