Patent Number: 7,355,755

Title: Image processing apparatus and method for accurately detecting character edges

Abstract: An image processing apparatus includes an edge amount calculating device configured to calculate edge amounts of an image in a plurality of directions for each of a plurality of frequency bands of the image. A character edge area determination device determines, based on the calculated edge amounts, whether or not a selected picture element of the image is of a character edge area. A sharpness control device corrects a frequency characteristic of the image by performing a first correction to the edge amounts when the selected picture element is determined to be of a character edge area by the character edge area determining device, and by performing a second correction to the edge amounts when the selected picture element is determined not to be of a character edge area by the character edge area determining device.

Inventors: Suino; Tooru (Sagamihara, JP), Shibaki; Hiroyuki (Tokyo, JP), Morimoto; Etsuo (Yokohama, JP)

Assignee: Ricoh Company, Ltd.

International Classification: H04N 1/405 (20060101); G06K 9/40 (20060101)

Expiration Date: 2020-04-08 0:00:00