Image-reading apparatus

An image-reading apparatus comprising:

• a light dividing means for dividing irradiated light so that a part of the light having a first wavelength is diffracted, and a part of the light having a second wavelength is transmitted;
• a first light measuring means for measuring an intensity of light entering into a first measuring area, and outputting first measurement information indicating the measured intensity;
• a second light measuring means for measuring an intensity of light entering into a second measuring area, and outputting second measurement information indicating the measured intensity;
• an image-forming means for forming an image of a subject for reading in the first measuring area, the image-forming means being located in an area into which light transmitted by the light dividing means enters, and that forms a virtual image in the second measuring area, using light diffracted by the light dividing means;
• and
• a generation means for correcting the first measurement information on the basis of the second measurement information, when generating image information representing an image of the subject for reading.