Improved three-dimensional localization of multiple small objects in close proximity in digital holography

Using intensity gradient- or sparsity-based focus metrics, the ability to accurately localize the three-dimensional (3D) position of a small object in a digital holographic reconstruction of a large field of view is hindered in the presence of multiple nearby objects. A more accurate alternative method for 3D localization, based on evaluation of the complex reconstructed volume, is proposed. Simulations and experimental data demonstrate a reduction in depth positional error for single objects and a notably improved axial resolution of multiple objects in dose proximity. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License.

Automated summary

Using intensity gradient- or sparsity-based focus metrics for accurately localizing small objects in digital holographic reconstructions of large fields of view is challenging in the presence of multiple nearby objects. This study proposes a more accurate alternative method based on evaluating the complex reconstructed volume, which demonstrates reduced depth positional error for single objects and notably improved axial resolution for multiple objects in close proximity. Published under a Creative Commons Attribution 4.0 License by The Optical Society.