1. School of Mechanical Engineering and Automation, Beijing University of Aeronautics and Astronautics, Beijing 100083, China;
2. School of Mathematical Sciences, Peking University, Beijing 100871, China
An industrial computed tomography(ICT) imaging method to enlarge the field of view was proposed to execute the rapid CT test of large objects. Its projection data rebin pre-processing method and filter back-projection reconstruction algorithm were deduced. The pre-processing method is from the fact that there exists the data redundancy for 3rd scan ICT. It creates the function mapping relationship between fan beam projections and parallel beam projections. This method can rebin the two groups of incomplete fan beam projections acquired by the detector at two positions into one group of complete parallel beam projections to meet the requirement of the reconstruction algorithm. The computer simulation results prove the validity of the proposed method to large objects. Analysis shows that its field of view is 1.8 times larger than that of 3rd scan ICT. This method can be implemented with the table with the transverse movement and the rotation movement and is easy to compatible with 3rd scan ICT without extra hardware requirements.
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