Camera orientation and 3D-deformation measurement by use of cross gratings

Abstract

The orientation of stereo cameras in a close range environment is derived by a modified bundle block adjustment, using the cross coordinates of a shifted high quality grating. By means of the HOUGH-transform, approximate grating coordinates are determined, which are used to calculate the final coordinates fully automatically with a correlation filter technique. The stereo setup is applied to measure the 3D-deformation on the surface of a cold welded CuAl tension specimen supplied with a titanium dioxide cross grating.