1. A distance information acquisition apparatus which captures the image of an object with a specified pattern projected, analyzes the captured image, and obtains distance information associated with said object, said apparatus comprising: a pattern projection module which projects a pattern onto said object, wherein said pattern is formed by combining said element groups, each element group comprising at least three types of elements having optically identifiable characteristics; an image capturing module which is placed with a specified distance from said pattern projection module and captures the image of an object having said pattern projected; and a correspondence determination module configured to determine which element in a captured image obtained by said image capturing module belongs to which element group in said pattern based on optical characteristics and position coordinates of said element in the captured image, wherein a specification result of said correspondence specify module is used to find distance information associated with said object.