A Novel Method for Enhancing the Image Quality of Neutron Projection Image

Neutron imaging technology is a novel non-destructive testing technique that combines nuclear technology with digital imaging technology. Neutron radiation has significant advantages in detecting light elements and isotopes, making it complementary to X-ray imaging. This paper focuses on lithium-ion batteries and addresses the high level of speckle noise and the low brightness and clarity of neutron projection images. To improve the image quality of neutron projection images, this study proposes methods for noise suppression and image enhancement. Firstly, the median filtering algorithm is utilized to remove speckle noise in the image, and then the gradient operator is applied to sharpen the image and reduce the blurring effect caused by the filtering algorithm. In terms of image enhancement, the quality of the image is improved from two aspects: brightness adjustment and edge sharpening, aiming to enhance image details and improve image contrast. This study tests the algorithm using real neutron projection images and compares it with seven typical image processing algorithms, using peak signal-to-noise ratio, image feature similarity index, average gradient, and no-reference structural clarity as evaluation indicators for image quality. The experimental results show that the proposed method can effectively remove speckle noise in neutron projection images of lithium batteries, significantly improve image clarity and contrast. Compared with the comparative methods, the proposed method has the best edge-preserving ability, the highest signal-to-noise ratio, and clearer image details. In addition, testing with neutron projection images of three non-lithium battery samples demonstrates the good universality of the proposed method in enhancing neutron projection images.