An image reading device includes: a first light source that irradiates light on a first side of an object; a memory that stores a plurality of parameters for controlling an intensity of the light emitting devices, each of the plurality of parameters corresponding to one of a plurality of groups; a controller that controls an intensity of the light emitting devices in response to one of the plurality of parameters stored in the memory; a first image reading unit that reads reflected light from the first side and generates monochrome image data on the basis of the read reflected light; and a second image reading unit that reads reflected light from the second side and generates monochrome image data on the basis of the read reflected light.