A general stitching measurement for stereo deflectometry

Abstract

A slope stitching algorithm is proposed to fulfill the measurement of a large object under the limited field of view in a stereo deflectometry system. The tested object can be easily divided into three sub-apertures under a unique world coordinate system w.r.t. the valid regions of the two cameras. Then the sub-apertures are stitched via slopes instead of point cloud. And, to produce a much smoother slope in the common regions of two cameras, a weighted average method is used to guide the merging process of the slope. The method expands the measurement area into a binocular combination area without the need for predefined markers or moving any devices. Experimental results confirm the feasibility and efficiency of our proposed algorithm, highlighting its advantages in testing large-size optical elements with high accuracy and cost-effectiveness.