IMAGE READING APPARATUS AND IMAGE READING METHOD

摘要

An image reading apparatus capable of recognizing edge portions of an original image with precision is provided. The image reading apparatus uses an image reading unit to scan an original being conveyed and read an image of the original. The image reading apparatus includes an edge information obtaining unit and an edge determining unit. The edge information obtaining unit detects an image of an edge portion of the original image and obtains, for each point in a main scanning direction, edge information, which indicates whether or not an edge portion image is detected at the point in a sub-scanning direction. The edge determining unit conducts detection from at least one of two directions of the main scanning direction to detect a point where a given number of successive edge portion images are detected, and obtains an edge portion based on the detected point.

主权项

1. An image reading apparatus, comprising:
a tray on which an original is to be placed; a conveyor configured to convey the original placed on the tray; an image reading unit configured to read an image of the original that is being conveyed by the conveyor to output image data; an edge information obtaining unit configured to detect an edge from image data of a plurality of lines near a front end of the original, and to obtain, for each point in a main scanning direction, edge information, which indicates whether or not an image of an edge portion is detected at the each point, the main scanning direction being orthogonal to a conveying direction in which the original is conveyed; and an original end portion detector configured to detect, based on the edge information, a main scanning point where a given number of successive edge portion images are detected in the main scanning direction, to thereby detect at least one end portion of the original in the main scanning direction in the image data.