• LD-RSM achieves a long working distance of 22.23 mm and an optical resolution of 4.92 μm, overcoming the limitations of conventional smartphone microscopes for industrial in situ inspection.
• The system employs a reflective optical path with a beam splitter, enabling illumination and imaging on the same side—critical for non-destructive testing of metallic mesh.
• DW-RPCA, combining spectral filter fusion, Hough transform, and double-threshold segmentation, delivers high pixel-level detection accuracy with f-values of 0.856 (square) and 0.848 (circular) metallic mesh.
• This portable, cost-effective smartphone-based microscopy approach demonstrates strong potential for real-world in situ quality control in transparent electromagnetic shielding film production.