An Improved Geometric Calibration Method for Accurate Phase Measuring Deflectometry

Abstract This paper presents a precise and fully automated calibration method for deflectometry. We propose a comprehensive set of calibration procedures, complemented by an enhanced optimization algorithm, to substantially improve the system’s measurement performance. The method utilizes a reference flat mirror to reflect the image of a checkerboard pattern displayed on an LCD screen at arbitrary angles. By exploiting the system constraints and camera images captured from multiple perspectives, we compute the optimized geometric parameters. Experimental results demonstrate that this calibration approach significantly enhances measurement accuracy.