Search results for "Specular surface"
showing 3 items of 3 documents
Vision system for defect imaging, detection, and characterization on a specular surface of a 3D object
2002
Abstract A vision system capable of imaging, detecting, and characterizing defects onto highly reflective, non-plane surfaces, is presented in this paper. Defects are typically dust, and hair located under the metallic layer of packaging products used in cosmetic industries. The vision system comprises an innovative lighting solution to reveal defects onto highly reflective non-plane surfaces. Several image acquisitions are performed to build a synthetic image, where defects clearly appear white on a mid-gray background. Our lighting system allows imaging defects on various-shaped objects. The vision system measures the defect size to make a decision on the product rejection. The authors as…
3D reconstruction of external and internal surfaces of transparent objects from polarization state of highlights
2014
A vision-based method is proposed to measure the 3D shape of external and internal surfaces (not accessible) of smooth transparent objects. Looking at the reflections of point sources on a specular surface with a polarimetric camera, we combine the measurements of two techniques: shape from distortion and shape from polarization. It permits us to recover the position and orientation of the specular surface for each detected point. The internal surface of transparent objects exhibiting as well a specular component, the same technique is used on the highlights coming from the back surface, taking into account the refraction by using polarimetric ray tracing.
3 D digitization of specular metallic surfaces by means of infrared imaging
2012
For the past twenty years, the need for three-dimensional digitization of manufactured objects has increased significantly and consequently, many experimental techniques and commercial solutions have been proposed. However, difficulties remain for the acquisition of optically non cooperative surfaces, such as transparent or specular ones. Since the working principle of conventional scanners is based on the acquisition of the diffuse part of the reflection, transparency and specular reflections may cause outliers. To address highly reflective metallic surfaces, we propose the extension of a non conventional technique that was originally dedicated to glass objects, called “Scanning from Heati…