Circle Fitting to Overcome Vignetting Effect of Afocal Tracking System

A focal tracking system is a tracing system that tracks a special marker called a focal marker. The cameras of a focal tracking system obtain images including bokeh which is shown from the a focal marker. Finding accurate center of bokeh is important for high precision position tracking of a focal marker. However, a focal tracking system suffers from vignetting effect which makes it difficult to find the accurate center of the bokeh. In this paper, a method to find the accurate center of the bokeh is introduced which can improve the accuracy of a focal tracking system.