1. An image processing apparatus comprising: an image analysis unit configured to acquire a distribution condition of feature points in an entire input image and a distribution condition of feature points in each of a plurality of small regions set in the input image, through image analysis; a target point number setting unit configured to set a target point number for each small region, based on the distribution condition of feature points in the entire input image, the target point number indicating the number of feature points which are to be detected during feature point detection; an expected point number setting unit configured to set an expected point number for each small region, based on the distribution condition of feature points in the small region, the expected point number indicating the number of feature points which are expected to be detected in the small region during feature point detection; a comparison unit configured to compare the target point number and the expected point number for each small region; a sensitivity setting unit configured to set detection sensitivity during feature point detection for each small region, based on the comparison result of the comparison unit; and a feature point detection unit configured to perform feature point detection according to the detection sensitivity set by the sensitivity setting unit.