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:
Nov. 09, 1993
Filed:
Oct. 31, 1991
Hiroki Kanno, Yokohama, JP;
Hitoshi Yoneda, Kawasaki, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
This invention utilizes the fact that 'a maximum density difference in a window within a predetermined range including a pixel of interest is large for a character region, and is small for a photograph region.' A maximum density difference of an image within a predetermined range is calculated as a feature amount. A quantization error of pixels around a pixel of interest is calculated, and then, a correction amount is calculated by proportionally distributing the quantization error in accordance with the feature amount calculated by a feature amount calculator. The correction amount is added to an image signal of the pixel of interest to form a compensation image signal, and the compensation image signal is quantized.