An image processing apparatus includes an estimation unit, a noise reduction unit, and an output unit. The estimation unit estimates a scattered-ray component contained in a radiation image acquired by irradiating an object with a radiation, wherein the scattered-ray component originates from a scattered ray which is a radiation scattered in the object. The noise reduction unit reduces a noise component included in the radiation image in accordance with first noise information obtained from the radiation image and second noise information obtained from a scattered-ray reduction image obtained by reducing the scattered-ray component from the radiation image. The output unit outputs a correction image obtained by reducing the scattered-ray component and the noise component in the radiation image.