An image processing device includes a processor including hardware. The processor performs a color attenuation process on regions other than a yellow region in a captured image including a subject image to relatively enhance the visibility of the yellow region in the captured image. The processor detects a blood region that is a region of blood in the captured image based on color information of the captured image. The processor suppresses or stops an attenuation process on the blood region based on detection result of the blood region.
