1. An image reading apparatus comprising: at least three line sensors mutually spaced in a sub scanning direction to scan an original in the sub scanning direction; a platen arranged between the original and said at least three line sensors; a mover moving said platen at a rate relative to said at least three line sensors, said rate being different from that of the original relative to said at least three line sensors; an extractor extracting a feature pixel having a predetermined feature from each of at least three data output from said at least three line sensors; and a detector comparing said at least three data corresponding to a single location on the original to detect said feature pixel extracted from one of said at least three data, as a noise pixel if said feature pixel is not a feature pixel for each of said at least three data other than said one of said at least three data.