1. An image processing apparatus comprising; a detecting unit configured to detect, respectively from plural images obtained by imaging with plural imaging units a space in which plural persons exist, positions of the persons on the images; an associating unit configured to perform association of a same person in the plural images; a person position estimating unit configured to estimate positions of the persons in the space, based on the positions of the persons on the images detected from the plural images and a result of the association by the associating unit; a direction estimating unit configured to estimate eye directions of the persons, based on the plural images; and a distribution estimating unit configured to estimate a spatial distribution of positions gazed by the plural persons, based on the estimated positions of the plural persons in the space and the estimated eye directions of the plural persons.