An image processing apparatus includes a first image pick-up unit, a projecting unit that projects imaging light, an optical unit that transmits part of light entering from a first image pick-up direction and guides the part of the light to the first image pick-up unit while reflecting part of the imaging light projected from the projecting unit and outputting the reflected light in the first image pick-up direction, and reflects part of light entering from a second image pick-up direction and guides the part of the light to the first image pick-up unit while transmitting part of the imaging light projected from the projecting unit and outputting the part of the imaging light in the second image pick-up direction, and an attenuating unit that is movably placed between two positions.