An image processing apparatus includes: a dark correction unit configured to obtain a dark corrected image by removing a dark image obtained in a state without radiation irradiation from an object image obtained by radiation irradiation an addition value obtaining unit configured to analyze pixel values included in a plurality of dark corrected images and, based on an analysis result of the pixel values including a negative pixel value, obtain an addition value used to correct the negative pixel value and an adding unit configured to add the addition value to the pixel values of the dark corrected image.
