The image acquisition unit acquires an image captured by an endoscope. The extraction unit extracts a blood vessel of an observation target. The index value calculation unit calculates a plurality of blood vessel index values based on the blood vessel. The determination unit determines whether each of the plurality of blood vessel index values is a normal value or an abnormal value. The color information setting unit sets color information for an abnormal index value, which is the blood vessel index value determined to be the abnormal value by the determination unit, or sets color information for a normal index value, which is the blood vessel index value determined to be the normal value by the determination unit. The image generation unit generates an emphasized image, in which the blood vessel is emphasized, based on the color information.
