An image processing apparatus is provided in an imaging system having an image capturing unit. The image capturing unit is configured to irradiate a subject with light and to generate first image data representing a first image based on the light reflected from the subject and having first spectral characteristics, and to generate second image data representing a second image based on the light reflected from the subject and having second spectral characteristics different from the first spectral characteristics. The image processing apparatus includes: a computing unit that determines a degree of correlation between the first image and the second image; and a control unit that causes the image capturing unit to generate the first image data at a preset frame rate, and controls timing to generate the second image data instead of the first image data based on a determination result of the degree of correlation.