An apparatus includes an acquisition unit configured to acquire a plurality of captured images of a target object imaged under a plurality of different conditions, a first calculation unit configured to calculate a first reflection characteristic of the target object for each pixel position of the captured images using a first spatial resolution based on the captured images, a determination unit configured to determine whether an angular resolution of the calculated first reflection characteristic is lower than a first threshold value, and a second calculation unit configured to calculate a second reflection characteristic of the target object using a second spatial resolution lower than the first spatial resolution based on the calculated first reflection characteristic in a case where the angular resolution is lower than the first threshold value.