An endoscope system is provided with a light source unit for generating illumination light, an image sensor for imaging an object of interest irradiated with the illumination light, an image signal obtaining section, a calculated image signal generator, and an image generator. The image signal obtaining section obtains a B1 image signal corresponding to violet light and a B2 image signal corresponding to blue light. The calculated image signal generator generates a calculated image signal from the B1 and B2 image signals. The image generator generates an image in which one of the B1 image signal and the B2 image signal is assigned to a luminance channel or a green channel and the calculated image signal is assigned to a remaining channel.