1. A distance measurement apparatus that calculates distance information from a first image and a second image that are image-captured with different image-capturing parameters, the distance measurement apparatus comprising: at least one processor operatively coupled to a memory, serving as: (i) a setting unit configured to set a first local region located in the first image and including a distance calculation target pixel, and a second local region located in the second image and corresponding to the first local region; (ii) an extraction unit configured to extract a plurality of shift regions, which are regions of which a shift amount from the second local region is within a predetermined range; (iii) a first calculation unit configured to calculate a correlation value between the first local region and each of the plurality of shift regions; (iv) a first decision unit configured to determine a correlation value used for calculating the distance information, based on the plurality of correlation values calculated by the first calculation unit; and (v) a second calculation unit configured to calculate the distance information on the distance calculation target pixel, based on the correlation value determined by the first decision unit.