Image reading apparatus that ensures high sn ratio by sufficient use of performance of image sensor, image reading method, and recording medium therefor

Abstract

An image reading apparatus includes a light source, a light-source control unit, a line sensor, an image data generating unit, and an image analysis unit. The line sensor includes a plurality of light receiving elements, a plurality of charge coupled devices, and a shift register. The image data generating unit generates image data according to electric charges output from the shift register. The image analysis unit determines whether transfer of the electric charges is normal, based on a contour reproduction status, being the status of reproduction of contours in test image data generated by reading of a test image having contours oriented intersecting an orientation whereby the plurality of light receiving elements are arranged. The light-source control unit adjusts the amount of light from the light source based on the determination by the image analysis unit.