Automated defect recognition Automation Contrast-to-noise ratio Deep learning Defect recognition Defects Digital X-ray radiography E-learning Image quality Image quality parameters Learning algorithms Learning systems Non destructive testing Nondestructive examination Performance Radiography images Semantic Segmentation Semantic segmentation Semantics Signal to noise ratio X ray radiography article automated defect recognition (ADR) contrast to noise ratio deep learning digital X-ray radiography experimental study human image quality non-destructive testing