  The need for single-camera 3D particle tracking methods is growing, among
others, due to the increasing focus in biomedical research often relying on
single-plane microscopy imaging. Defocusing-based methods are ideal for a
wide-spread use as they rely on basic microscopy imaging rather than requiring
additional non-standard optics. However, a wide-spread use has been limited by
the lack of accessible and easy-to-use software. DefocusTracker is an
open-source toolbox based on the universal principles of General Defocusing
Particle Tracking (GDPT) relying solely on a reference look-up table and image
recognition to connect a particle's image and its respective out-of-plane depth
coordinate. The toolbox is built in a modular fashion, allowing for easy
addition of new image recognition methods, while maintaining the same workflow
and external user interface. DefocusTracker is implemented in MATLAB, while a
parallel implementation in Python is in the preparation.
