A novel illumination technique for specular textured surfaces and its high performance implementation using auto-parallelization techniques

• Volkmar Wieser

The covering of high-end consumer devices using stainless steel slabs has aesthetic as well as hygienic reasons, and usually reflects the high quality of the product. Hence, surface defects on such facings devaluate the suggested high quality, which makes a visual quality control necessary. However, especially the quality control of specular, textured materials like brushed stainless steel cover plates must be done manually, which results in a time- and cost-intensive activity. Furthermore, the results of the verification done by several quality experts are not comparable in many cases, because of minor differences in fault characteristics, which could result in misinterpretation and misvaluation. Moreover, if a customer complaint occurs, it is difficult to comprehend at which stage of the process cycle (e.g., during production, delivery, or through customer) a surface defect (e.g., scratches) happens and who has to substitute the damaged cover plate with a defect-free part. Additionally, state-of-the-art illumination techniques usable for specular surfaces are either not applicable in industrial surroundings, too complex in the mechanical handling, or only limitedly suitable for this type of surfaces.