Review of phase measuring deflectometry

As a low cost, full-field three-dimensional shape measurement technique with high dynamic range, Phase Measuring Deflectometry (PMD) has been studied and improved to be a simple and effective manner to inspect specular reflecting surfaces. In this review, the fundamental principle and the basic concepts of PMD technique are introduced and followed by a brief overview of its key developments since it was first proposed. In addition, the similarities and differences compared with other related techniques are discussed to highlight the distinguishing features of the PMD technique. Furthermore, we will address the major challenges, the existing solutions and the remaining limitations in this technique to provide some suggestions for potential future investigations.