Tracker is a Java-based application that allows you to analyze a video clip or an image in order to determine multiple variables. The program is designed to be used in physics experiments in order to easily estimate the acceleration and velocity of a certain object.
The application uses the Xuggle video engine in order to load the video file and analyze the image details. In order to perform the analysis you need to identify the frames from the movie that you need to analyze and specify the position of the tracked object.
If you want to get accurate results, make sure that you calibrate the scale of the video by specifying the length of a certain object. Since the app is mainly used for physics experiments, it is recommended to use objects with known dimensions when recording the experiment.
This program needs to use multiple markers in order to identify the position of the object in the the key frames. You can select various marker types according to the type of experiment that you are performing.
For instance, you can use the Line Profile option to measure the brightness for a certain image area or Point Mass to describe the movement of a certain object such as a ball or car. Additional tracks include vectors, particle models and angle measurements.
The results of the analysis are immediately displayed in the plot view which are defined for each track. When creating a new marker or changing the marker position, the plot is automatically refreshed in order to provide accurate information.
If you need to analyze the exact coordinates, the Data Tool provides you with additional measurements and statistics. Here you can calculate the maximal, minimal and mean values with just a few clicks.
As a conclusion, Tracker is an easy to use analysis tool that can help you calculate variables by retrieving relevant data from a movie or image. It includes a complete documentation which makes it suitable for all user categories.