An information processing apparatus acquires a 2D image as a definition target of depth information, and accepts, for the acquired 2D image, an input of point information for designating two points on the image and an input of line segment information indicating a first line segment as a standard of a depth. The apparatus sets, for a point on a second line segment connecting the two points on the 2D image indicated by the point information, depth information based on the first line segment indicated by the line segment information.