A simple and effective method for the removal of gamma white spots noise in fast neutron images

Fast neutron radiography technology has unique application advantages in the field of non-destructive testing. However, due to the interaction between the gamma rays and the charge-coupled device camera, a large amount of gamma white spots noise is attached to the fast neutron images, which affects the subsequent analysis. In this paper, we propose a simple and effective method to remove gamma white spots noise in fast neutron images. First, the image is down-sampled by the dilated down-sampling method to reduce the influence of noise. Then, the existence of gamma white spots noise is accurately identified by noise detection. Finally, the image is denoised using an improved median filtering method. In order to verify the performance of the proposed method, several commonly used noise reduction methods and the proposed method are used to conduct test experiments on both simulated and fast neutron images, and several image quality evaluation indices are used for quantitative assessment. The results show that the proposed method not only performs well in visual effects but also achieves satisfactory results in evaluation indices.