3D measurements of micro-objects based on monocular wide-field optical microscopy with extended depth of field

Monocular rotational microscopes suffer from shallow depth of field and reduced field of view. Consequently, we propose monocular wide-field optical microscopy with extended depth of field to enable accurate 3D measurements of micro-objects. We use a liquid lens and a 4f system to extend the system's depth of field and two additional rotational reflectors to capture multi-view image sequences. In addition, we increase the number of expansion directions in the patch-based multi-view stereo algorithm and optimize the expansion radius. Our approach outperforms that based on the patch-based multi-view stereo method and achieves a high relative measurement accuracy of 1.9%. Research Highlights This study proposes 3D measurements of micro-objects via monocular rotational microscopy. The depth of field is extended by the use of a liquid lens and a 4f system. Our approach outperforms that based on the patch-based multi-view stereo method and achieves a high relative measurement accuracy of 1.9%.