HD-RTI: An adaptive multi-light imaging approach for the quality assessment of manufactured surfaces

•High Dynamic Range (HDR) technique is adapted and implemented automatically for Reflectance Transformation Imaging (RTI), called HD-RTI.•Reflectance Transformation Imaging augmented with High Dynamic Range Technique (HD-RTI) allows better capturing and modelling of specular surfaces.•RTI coupled with High Dynamic Range technique (HD-RTI) permits adaptivity to observed surfaces.•HD-RTI allows efficient computation of saliency maps.•HD-RTI serves as means of visual quality assessment and inspection of manufactured surfaces. Reflectance Transformation Imaging (RTI) is a technique for estimating surface local angular reflectance from a set of stereo-photometric images captured with variable lighting directions. The digitization of this information fully fits into the industry 4.0 approach and makes it possible to characterize the visual properties of a surface. The proposed method, namely HD-RTI, is based on the coupling of RTI and HDR imaging techniques. This coupling is carried out adaptively according to the response at each angle of illumination. The proposed method is applied to five industrial samples which have high local variations of reflectivity because of their heterogeneity of geometric texture and/or material. Results show that coupling HDR and RTI improves the relighting quality compared to RTI, and makes the proposed approach particularly relevant for glossy and heterogeneous surfaces. Moreover, HD-RTI enhances significantly the characterization of the local angular reflectance, which leads to more discriminating visual saliency maps, and more generally to an increase in robustness for visual quality assessment tasks.