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:
Feb. 23, 1999
Filed:
Jun. 06, 1997
Shinji Asada, Tenjinkitamachi, JP;
Dainippon Screen Manufacturing Co., Ltd., Kyoto-fu, JP;
Abstract
An original image is divided into a plurality of pixel blocks each consisting of a plurality of pixels. A density histogram represented by an electric signal is obtained for each pixel block. Respective pixel blocks are analyzed to find adjacent pixel blocks which are uniform and continuous in density. If the pixel blocks thus found are continuous in density with the reference pixel blocks located at the corner of the original image, the pixel blocks are regarded as those representing the background portion of the original image. The numbers of pixels in the density histogram is corrected for each background pixel block, and highlight and shadow points for determining a gradation curve is determined. The gradation curve is set in a signal-converter to convert an image signal representative of the original image.