Image up-sampling algorithm for superposing images with different spatial resolutions

Abstract

Until recent days, dual-energy X-ray cargo inspection system was mainstream method of non-invasive cargo inspection system. However, due to the usage of X-ray beams, which interact with matters in the same way, the precision of material discrimination tended to be low. Hence, cargo inspection system using neutron beam and X-ray beam, which interact with matters in the opposite way is on development. In the neutron / X-ray cargo inspection system, in order to counter the image noise from the low source intensity of the neutron beam, neutron detector pixel has large size than that of the X-ray. This leads to lower spatial resolution of the neutron image, causing difficulty in superposing the images. In this study, an image up-sampling algorithm that uses cluster distribution of the X-ray image with high spatial resolution was developed. Upon the application of the proposed algorithm, the spatial resolution of the neutron image along with the quality of the material discrimination was enhanced.