1. An image processing apparatus comprising: a blurry image generation unit configured to generate a plurality of blurry images having a different blurriness level from an input image; an input unit configured to input print setting information to be used in printing of the input image; a calculation unit configured to calculate a size of a composite low-frequency image formed by compositing the plurality of blurry images based on the print setting information; a generation unit configured to generate a composite low-frequency image in the calculated size from the plurality of blurry images; and a processing unit configured to perform dodging processing on the input image using the generated composite low-frequency image.