Image reading apparatus, image forming apparatus, light quantity acquisition method and computer readable medium

摘要

An image reading apparatus includes: an image reading unit including a light source and a light receiving unit, and being capable of reading an image of a document sheet with predetermined plural reading conditions; a first light quantity information acquiring unit acquiring first light quantity information on a quantity of light emitted from the light source to a first white reference plate and received by the light receiving unit, for each reading condition; a second light quantity information acquiring unit acquiring second light quantity information on a quantity of light emitted from the light source to a second white reference plate and received by the light receiving unit, for fewer reading conditions than all the plural reading conditions; and a third light quantity information acquiring unit acquiring the second light quantity information for reading conditions other than the fewer reading conditions by using the acquired first light quantity information.