Spatial resolution improvement techniques for three dimensional industrial computed tomography(3D-ICT) have been researched in this paper.A cone-beam 3D-ICT scan mode was proposed to improve the spatial resolution by the quarter-detector offset.Its filter back-projection reconstruction algorithm based on the parallel beam rebin principle was deduced.Firstly this method acquires the two dimensional projection sequence by offsetting the detector center a quarter of the detector channel width with respect to the iso-center.Secondly it rebins these projects into parallel data.Finally it doubles the sampling frequency of parallel data with the symmetry between two projection view angles with an angle interval 180°.Computer simulation results prove the correction and the validity of this algorithm.Using this algorithm
the spatial resolution can be improved approximate 100% along the horizontal reconstruction direction.