This paper presents an adaptive focus stacking method for large depth-of-field (DOF) 3D microscopic structured-light imaging systems. Conventional focus stacking methods typically capture images under a series of pre-defined focus settings without considering the attributes of the measured object. Therefore, it is inefficient since some of the focus settings might be redundant. To address this problem, we first employ the focal sweep technique to reconstruct an initial rough 3D shape of the measured objects. Then, we leverage the initial 3D data to determine effective focus settings that focus the camera on the valid areas of the measured objects. Finally, we reconstruct a high-quality 3D point cloud using fringe images obtained from these effective focus settings by focus stacking. Experimental results demonstrate the success of the proposed method.
Three-dimensional (3D) shape measurement based on the fringe projection technique has been extensively used for scientific discoveries and industrial practices. Yet, one of the most challenging issues is its limited depth of field (DOF). This paper presents a method to drastically increase DOF of 3D shape measurement technique by employing the focal sweep method. The proposed method employs an electrically tunable lens (ETL) to rapidly sweep the focal plane during image integration and the post deconvolution algorithm to reconstruct focused images for 3D reconstruction. Experimental results demonstrated that our proposed method can achieve high-resolution and high-accuracy 3D shape measurement with greatly improved DOF in real time.
more » « less- NSF-PAR ID:
- 10196207
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Optics Express
- Volume:
- 28
- Issue:
- 21
- ISSN:
- 1094-4087; OPEXFF
- Page Range / eLocation ID:
- Article No. 31197
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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