Figure 1. Program flow and visualization interface of TrackNTrace.

First, a list of movies or a previously saved settings file is loaded before the main GUI is initialized. There, plugins for steps 2–4 are chosen and their settings adjusted for each movie. At any time during parameter tuning, a preview for an arbitrary part of the current movie can be computed and visualized. The visualizer is able to display the output from all stages on-screen and as a histogram. Selecting a candidate, localization, or track showcases the respective plugin-specific output (e.g., fitted parameter values). Typical issues such as undetected candidates, badly refined positions, or prematurely ending tracks, indicated by the white arrows, can be identified and corrected by choosing different settings. After (repeated) parameter adjustment for all movies, the actual processing starts, saving each movie’s output data along with the chosen settings in a single file.