1. An image processing apparatus comprising: a calculation unit configured to calculate, based on a pixel value of a pixel of interest and a pixel value of a pixel around the pixel of interest, a spatial frequency around the pixel of interest and a statistic value of pixel values around the pixel of interest; a storage unit configured to store correction parameters corresponding to sets of spatial frequencies and statistic values; an acquisition unit configured to acquire, from said storage unit, a correction parameter corresponding to the spatial frequency around the pixel of interest and the statistic value of the pixel values around the pixel of interest, as a correction parameter for the pixel of interest; and a correction unit configured to correct the pixel value of the pixel of interest using the correction parameter for the pixel of interest.