Image forming apparatus capable of reading image on original document and forming image

An image forming apparatus that reads an image on an original document and forms an image based on the read image, the image forming apparatus comprising:

• a light source comprising a first original light source that emits light having a first spectrum, and a second original light source that emits light having a second spectrum, and emits the light having the first spectrum and the light having the second spectrum;
• an image reading device that generates image data of an RGB color system according to reflected light of the light having the first spectrum from the original document and reflected light of the light having the second spectrum from the original document;
• an image forming device that forms, based on the image data, an image with a recording agent of a CMYK color system;
• and
• a control device including processor, and that makes a determination of, as a ratio between an amount of reflected light of the light having the first spectrum from a calibration original document prepared for calibration of the light having the second spectrum and a calibration reference value set as a reference of an amount of reflected light of the light having the first spectrum, a correction value for use in calibrating an amount of the light having the first spectrum,
• wherein the controller corrects the correction value by multiplying the calibration reference value for use in the determination of the correction value by an added value in which a division result obtained by dividing a Z reference value set as a reference of a Z value in an XYZ color system obtained based on the amount of reflected light of the light having the first spectrum by the Z value is added to a weight according to a difference result obtained by subtracting the Z value from the Z reference value.