ASFC-Net: An Enhanced YOLOv8 for Heavy-Haul Rail Surface Defect Inspection via Asymmetric Spatial–Frequency Collaboration
Weak rail-surface defects are difficult to detect because their localized evidence can be attenuated during downsampling and confused with structured rail texture. Across 2895 training and validation images, the low-, mid-, and high-frequency bands contain 97.23 %, 2.04 %, and 0.73 % of the whole-image spectral energy,...