3D reconstruction of the specular surface using an iterative stereoscopic deflectometry method.

Area of Science:

• Optical Metrology
• Computer Vision
• Surface Reconstruction

Background:

• Phase measuring deflectometry (PMD) is a key technique for 3D measurement of specular surfaces.
• Existing methods face challenges like monoscopic ambiguity and time-consuming pixel searching in stereoscopic PMD.
• Efficient and accurate reconstruction of specular surfaces remains a significant challenge in optical metrology.

Purpose of the Study:

• To develop an iterative reconstruction algorithm for stereoscopic phase measuring deflectometry systems.
• To eliminate the need for time-consuming pixel searching during specular surface reconstruction.
• To improve the accuracy and efficiency of 3D specular surface measurement.

Main Methods:

• An iterative reconstruction algorithm is proposed for stereoscopic phase measuring deflectometry.
• A coarse-to-fine optimization method is used to obtain an initial seed point on the specular surface.
• The algorithm utilizes a pinhole model for iterative surface form updates, starting from an initial plane approximation.

Main Results:

• The proposed iterative algorithm successfully reconstructs specular surfaces without pixel searching.
• Simulations and experimental results demonstrate the feasibility and efficiency of the method.
• The algorithm shows comprehensive accuracy and robustness in specular surface measurement.

Conclusions:

• The developed iterative reconstruction algorithm significantly enhances stereoscopic phase measuring deflectometry.
• This method offers a faster and more accurate approach to 3D specular surface reconstruction.
• The technique provides a robust solution for challenging optical metrology applications.