1. An image reading apparatus comprising: a plurality of line sensors mutually spaced in a sub scanning direction to scan an original moving in the sub scanning direction, wherein the plurality of line sensors generate a corresponding plurality of signals upon scanning the original; a platen arranged between a movement pathway of the original, and said plurality of line sensors; a mover configured to move said platen at a rate relative to said plurality of line sensors, said rate being different from a movement rate of the original relative to said plurality of line sensors; a first extractor configured to extract, from a first signal of the plurality of signals, a first feature pixel from a region having a predetermined feature of a first level; a second extractor configured to extract, from each of said plurality of signals other than the first signal, one or more second feature pixels from a region having said predetermined feature of a second level; and a detector configured to detect a noise pixel by comparing the plurality of data corresponding to a particular location on the original, the detector being configured to determine whether the first feature pixel and the one or more second feature pixels correspond to the particular location, wherein upon detecting that the first feature pixel corresponds to the particular location and none of the one or more second feature pixels correspond to the particular location, the detector detects the first feature pixel as a noise pixel; and wherein upon detecting that the first feature pixel corresponds to the particular location and at least one of the one or more second feature pixels corresponds to the particular location, the detector detects the first feature pixel as not a noise pixel.