Abstract: An image reading apparatus includes: a light source that generates light by synthesizing light from different illuminants and irradiates an irradiated object with the generated light; a reading unit that reads light irradiated by the light source and reflected by the irradiated object and generates image information in a first color space on the irradiated object; a color conversion unit that converts the image information in the first color space into image information in a second color space with a color conversion factor group; and a color conversion factor group setting unit that acquires from the reading unit the image information generated by using, as the irradiated object, a color sample formed in a color of light emitted by one of the illuminants, determines the color conversion factor group to be used, according to the acquired image information, and sets the color conversion factor group to the color conversion unit.

Abstract: An image reading apparatus includes: a light source that irradiates a document sheet with light; a light receiving unit that receives reflected light from the document sheet; and a color determination unit that performs color determination as to whether an image of the document sheet is any one of a monochrome image and a color image. The color determination unit performs the color determination as to whether the image of the document sheet is any one of a monochrome image and a color image by comparing chroma information of the image of the document sheet read by the light receiving unit with a threshold calculated from chroma information obtained by reading an image having a predetermined chroma.

Abstract: An image reading apparatus includes: a light source that generates light by synthesizing light from different illuminants and irradiates an irradiated object with the generated light; a reading unit that reads light irradiated by the light source and reflected by the irradiated object and generates image information in a first color space on the irradiated object; a color conversion unit that converts the image information in the first color space into image information in a second color space with a color conversion factor group; and a color conversion factor group setting unit that acquires from the reading unit the image information generated by using, as the irradiated object, a color sample formed in a color of light emitted by one of the illuminants, determines the color conversion factor group to be used, according to the acquired image information, and sets the color conversion factor group to the color conversion unit.