title: Refining particle positions using circular symmetry.
abstract: Particle and object tracking is gaining attention in industrial applications and is commonly applied in: colloidal, biophysical, ecological, and micro-fluidic research. Reliable tracking information is heavily dependent on the system under study and algorithms that correctly determine particle position between images. However, in a real environmental context with the presence of noise including particular or dissolved matter in water, and low and fluctuating light conditions, many algorithms fail to obtain reliable information. We propose a new algorithm, the Circular Symmetry algorithm (C-Sym), for detecting the position of a circular particle with high accuracy and precision in noisy conditions. The algorithm takes advantage of the spatial symmetry of the particle allowing for subpixel accuracy. We compare the proposed algorithm with four different methods using both synthetic and experimental datasets. The results show that C-Sym is the most accurate and precise algorithm when tracking micro-particles in all tested conditions and it has the potential for use in applications including tracking biota in their environment.
authors.affiliation: Department of Physics, Umeå University, Umeå, Sweden.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Rodriguez
authors.affiliation: Department of Physics, Umeå University, Umeå, Sweden.
authors.forename: Hanqing
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Physics, Umeå University, Umeå, Sweden.
authors.forename: Krister
authors.initials: K
authors.lastname: Wiklund
authors.affiliation: Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden.
authors.forename: Tomas
authors.initials: T
authors.lastname: Brodin
authors.affiliation: Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden.
authors.forename: Jonatan
authors.initials: J
authors.lastname: Klaminder
authors.affiliation: Department of Chemistry, Umeå University, Umeå, Sweden.
authors.forename: Patrik
authors.initials: P
authors.lastname: Andersson
authors.affiliation: Department of Physics, Umeå University, Umeå, Sweden.
authors.forename: Magnus
authors.identifier: http://orcid.org/0000-0002-9835-3263
authors.initials: M
authors.lastname: Andersson
mesh_terms: D000465:Algorithms; D007091:Image Processing, Computer-Assisted; D008853:Microscopy; D010316:Particle Size; D059629:Signal-To-Noise Ratio; D012984:Software