1. An image reading apparatus comprising: a plurality of line sensors mutually spaced in a sub-scanning direction to scan an original in the sub-scanning direction, wherein data of the plurality of line sensors are composited together to form an image of the original; a platen arranged between the original and said plurality of line sensors; a mover moving said platen at a rate of movement of the original relative to said plurality of line sensors, said rate being different from that of the original relative to said plurality of line sensors; an extractor configured to extract a feature pixel having a predetermined feature from any of the plurality of data corresponding to said plurality of line sensors; and a detector configured to identify a noise pixel by comparing said plurality of data corresponding to a single location on the original and identifying the feature pixel as a noise pixel if said feature pixel is detected for one of said plurality of data, and is not detected as a feature pixel for each of the other said plurality of data, wherein said detector includes a determiner determining that a value of a first pixel of one of said plurality of data and that of a second pixel related to said first pixel has a predetermined relationship, and if said feature pixel extracted from one of said plurality of data further satisfies a condition for determination by said determiner, said feature pixel is detected as a noise pixel.