IMAGE DISTORTION CORRECTION DEVICE, IMAGE READER, IMAGE FORMING DEVICE AND PROGRAM

PROBLEM TO BE SOLVED: To provide a book document image distortion correction device and program in which correction accuracy can be improved even when a scanner parameter is known or unknown. SOLUTION: A scanned image obtained by reading a book document image placed on a scan plane is expanded in a main scanning direction and a sub-scanning direction to perform distortion correction so that a page binding part can be approximately parallel to the main scanning direction. The distance between a book document and the scan plane is found from the scanned image and optical axis position information of a scanner lens that reads the scanned image and on the basis of this distance, the distortion of the scanned image in the sub-scanning direction is corrected. When the optical axis position information of the scanner lens is indistinct, the distortion of the scanned image in the main scanning direction is corrected, a character-circumscribed rectangle is then extracted from the corrected image and on the basis of the form of the character-circumscribed rectangle, the distortion in the sub-scanning direction is corrected. COPYRIGHT: (C)2004,JPO&NCIPI