TLD can be downloaded for testing. We provide a precompiled demo (Windows) and a source code.

A license has to be purchased for using TLD in closed source projects. The licencing is managed the University of Surrey: Commercial License

TLD is an award-winning, real-time algorithm for tracking of unknown objects in video streams. The object of interest is defined by a bounding box in a single frame. TLD simultaneously Tracks the object, Learns its appearance and Detects it whenever it appears in the video. The result is a real-time tracking that typically improves over time.

Due to its learning abilities, TLD has been advertised under name Predator. The video to the right introduces Predator and demonstrates several potential applications.

TLD was developed by Zdenek Kalal during his PhD thesis supervised by Krystian Mikolajczyk and Jiri Matas. The main contributions of TLD were presented at international computer-vision conferences. For his work on TLD, Zdenek Kalal was awarded the UK ICT Pioneers 2011.

More examples

Fast motion


Similar objects

Low-textured objects

Key Features

More Information



(c) 2011 Zdenek Kalal