Image quality enhancement in Neutron Computerized Tomography based on projection exposure time adjustment

This paper presents a proposed procedure for neutron radiography image enhancement through studying the effect of the projection exposure time on the quality of Neutron Computerized Tomography (NCT) image. A sample was exposure at the Egyptian Second Research Reactor (ETRR-2) NCT facility with projection exposure time varying from one second to six seconds at reactor power operation of 17 MW_th. The NCT image was corrected against the read-out noise using flat and dark current images. Then, the Region of Interest (ROI) is selected based on an automatic threshold of the occurrence histogram of the image variance. After that, the image was normalized and filtered by median filter. The resultant images were evaluated qualitatively and compared with the images obtained from Octopus 8.5 software that is currently used in the Egyptian NCT facility. The results indicated that high-quality images had accomplished in comparison with Octopus 8.5 software without losing any information. In addition, with respect to quality measures, the image at the projection exposure time equal to 4 seconds is the best obtained image.