An image processing apparatus acquires a radiation image captured by irradiating an object with a radiation from a radiation source, estimates a scattered radiation image included in the acquired radiation image, and outputs a corrected image obtained by reducing the scattered radiation image from the acquired radiation image. The image processing apparatus estimates the scattered radiation image by applying a scattered radiation model for obtaining a scattered radiation component to the acquired radiation image based on a specific frequency component of an output of a first function and a specific frequency component of an output of a second function different from the first function.
