You can easily annotate lines and export them for later use. For now only annotating of straight lines is implemented. This is due to the initial requirements of the project. We only needed straight lines. Nonetheless, new features can be added easily. Application can be extended by adding support for annotating of curved lines.
Also you can brush over subjects of interest. For our research purpose, we wanted to annotate player segments, so we used means of brushing over players to annotate them. As can be seen in the picture, a transparent red brush overlays player segments. As user brushes over segments of interest, its output is saved in a format that can later be edited. So this process isn't a one-time-only kind of process. Ability to label each annotated segment is in the future feature list.
This application has a very responsive and user friendly interface. This interface has been tested constantly while adding new features. So it makes the process of annotating comfortable and fun for the user. Just like other useful applications, this application has lots of keyboard shortcuts. So you don't have to click on any button, just move the mouse cursor :)