Imaging system with calibration target object

An imaging system based on light triangulation for capturing information on three dimensional characteristics of a target object by means of one or more cameras arranged at first one or more positions for detecting light reflected from said target object, said system comprising said one or more cameras at said first positions and a calibration target object within respective field of view of said cameras so that the cameras are able to detect light reflected from one or more surface structures of the calibration target object, said one or more surface structures having a first surface structure comprising one or more regular right pyramidal recesses and one or more regular right pyramids, with their respective bases in the same plane and their respective apexes at the same orthogonal distance from that same plane, where the lateral faces of the respective regular right pyramids correspond to the lateral faces of the regular right pyramidal recesses, there being at least three regular right pyramids or at least three regular right pyramidal recesses, wherein the base of at least one of said regular right pyramidal recesses shares at least one side with the base of at least one of said regular right pyramids, such that each pair of lateral faces sharing side are located in a common plane.