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.