Influence of Lens and Perspective Distortion on Optical Surface Metrology Instrumentation

Abstract

For any surface metrology system that obtains measurement with the aid of an imaging system, distortion must be carefully scrutinized. Both intrinsic lens distortion and perspective distortion embed surface error distributions that skew the interpretation of resultant surface maps. Either displaces acquired information due to the imaging process. Here, we quantify the origins of distortion, its modeling philosophy, and the effects of its digital correction procedure. This study includes simulation for lens-distorted systems such as interferometers and perspective-distorted systems such as monoscopic fringe projection profilometry and deflectometry. Summarily, this study hopes to clarify differences in low-order shape between surface metrology instrument measurements in which surface maps were not rectified for distortion. © 2022 SPIE.