A novel approach is presented for the location of discrete targets images with subpixel accuracy. It can be adopted as first stage of any method that uses planar and no-planar grids with circular, square or cross shaped targets in order to calibrate close range cameras. The approach has been performed on several calibration sessions each of them followed by the three-dimensional reconstruction of a reference object that was previously measured through a coordinate measuring machine. The performance of the proposed approach has been expressed in terms of deviation between the reference coordinates and the corresponding ones provided by triangulation. The results obtained have also been compared with those achieved through ShapeCaptureTM, a software widely used in photogrammetry for camera calibration and 3D model reconstruction from images.