caa a22 4500 606173110 CHVBK 20210128100731.0 cr unu---uuuuu 210128e20150601xx s 000 0 eng 10.1007/s10921-015-0290-z doi (NATIONALLICENCE)springer-10.1007/s10921-015-0290-z Defect Detection Improvement of Digitised Radiographs by Principal Component Analysis with Local Pixel Grouping [Elektronische Daten] [Amir Movafeghi, Effat Yahaghi, Noureddin Mohammadzadeh] Radiographic inspection is one of the most important techniques among non-destructive testing methods. Radiographic images are often very noisy and the image quality and the interpreter's experience can affect the inspection of radiographs and their evaluation. In this research, principal component analysis (PCA) with local pixel grouping (LPG) algorithms was used for image enhancement for radiograph image interpretation. In this method, a pixel and its neighbors are considered as a vector variable for preservation of radiography image local structure. This method is a statistical method that uses an orthogonal property to transform and convert a set of observations of possibly correlated variables into a set of values of uncorrelated variables. Here, the PCA-LPG denoising algorithm has been applied to radiographic images with different defects to obtain denoised images. The results show that the contrast of denoised radiography images is better than the original image and the defects are much clearer. Also, the evaluation of the image quality enhancement show the contrast to noise level increases almost two times by the proposed PCA-LPG method. Springer Science+Business Media New York, 2015 Defect detection nationallicence Digitised radiographs nationallicence Principal component analysis nationallicence Local pixel grouping nationallicence Nondestructive testing nationallicence Movafeghi Amir Nuclear Safety and Radiological Protection Research Group, Nuclear Science and Technology Research Institute (NSTRI), Tehran, Iran aut Yahaghi Effat Department of Physics, Imam Khomeini International University, Qazvin, Iran aut Mohammadzadeh Noureddin Nuclear Safety and Radiological Protection Research Group, Nuclear Science and Technology Research Institute (NSTRI), Tehran, Iran aut Journal of Nondestructive Evaluation Springer US; http://www.springer-ny.com 34/2(2015-06-01), 1-6 0195-9298 34:2<1 2015 34 10921 https://doi.org/10.1007/s10921-015-0290-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10921-015-0290-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Movafeghi Amir Nuclear Safety and Radiological Protection Research Group, Nuclear Science and Technology Research Institute (NSTRI), Tehran, Iran aut NATIONALLICENCE 700 1- Yahaghi Effat Department of Physics, Imam Khomeini International University, Qazvin, Iran aut NATIONALLICENCE 700 1- Mohammadzadeh Noureddin Nuclear Safety and Radiological Protection Research Group, Nuclear Science and Technology Research Institute (NSTRI), Tehran, Iran aut NATIONALLICENCE 773 0- Journal of Nondestructive Evaluation Springer US; http://www.springer-ny.com 34/2(2015-06-01), 1-6 0195-9298 34:2<1 2015 34 10921