We achieve tomography of 3D volumetric natural objects, where each projected 2D image corresponds to a different specimen. Each specimen has unknown random 3D orientation, location and scale. This imaging scenario is relevant to microscopic and mesoscopic organisms, aerosols and hydrosols viewed naturally in a microscope. In-class scale variation inhibits prior single-particle reconstruction methods. We thus generalize tomographic recovery to account for all degrees of freedom of a similarity transformation. This enables geometric self-calibration in imaging of transparent objects. We make the computational load manageable and reach good quality reconstruction in a short time. This enables extraction of statistics that are important for a scientific study of specimen populations, specifically size distribution parameters.
We apply the method to study of plankton. Below are plankton images taken from Woods Hole Oceanographic Institution. The orientation and scale of similar plankton samples are recovered along with a statistical 3D density reconstruction.
Aviad Levis, Yoav Y. Schechner, Ronen Talmon,“Statistical Tomography of Microscopic Life”, Proc. IEEE CVPR, 2018.