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. 08, 2013
Filed:
Aug. 24, 2010
Kohei Furuya, Tokyo, JP;
Kohei Furuya, Tokyo, JP;
Canon Kabushiki Kaish, Tokyo, JP;
Abstract
An image processing apparatus generates, for an image, partial histograms by dividing a luminance histogram at downward convex parts of a frequency distribution of the luminance histogram. The image processing apparatus calculates, for a partial histogram selected from the partial histograms, a difference between a maximum frequency in each of all the partial histograms located on the first side of the selected partial histogram, and a minimum frequency within a luminance range from a luminance level of the maximum frequency to that of a maximum frequency in the selected partial histogram as a drop, and sets a maximum one of the drops calculated for the respective partial histograms as a drop. The image processing apparatus sets a weight, which becomes smaller as this drop is larger, for the selected partial histogram, and calculates a weighted average of the luminance histogram, thereby acquiring a luminance value for the tone correction.