An image processing unit includes an image acquisition unit, a blood vessel index value acquisition unit, and a blood vessel parameter calculation unit. The image acquisition unit acquires an endoscopic image captured by an endoscope. The blood vessel index value acquisition unit acquires a first blood vessel index value in a first observation condition and a second blood vessel index value in a second observation condition, as blood vessel index values of blood vessels of an observation target, using the endoscopic image acquired by the image acquisition unit. The blood vessel parameter calculation unit calculates a blood vessel parameter, using the first blood vessel index value and the second blood vessel index value.
