Patent ID: 6078703
Filing Date: 2000-06-20
Classification: H04N

Abstract:
An image reading apparatus comprising:image reading means for reading an original image, one main scan line by one main scan line, in a sub-scan direction;window setting means for setting a measuring window in a bit-map formation of image data obtained through said image reading means, in a manner in which said measuring window moves along an oblique line image which is formed in said bit-map formation of image data as a result of being read through said image reading means; andcenter of gravity calculating means for calculating the center of gravity of image data of pixels defined by said measuring window in said bit-map formation of said image data;window shifting control means for determining whether or not said measuring window is shifted according to a center of gravity calculation result of said center gravity calculating means; andposition error measuring means for measuring a reading pixel position error from said center of gravity calculated by said center of gravity calculating means.