Overview
Object Tracking (often translated as "Objektverfolgung" in German) is a technique from image processing and VFX post-production. It analyzes the movement of a specific object, surface, or distinctive image point across the frames of a shot and translates it into a motion path. This path provides values for position, rotation, and scaling, to which other image elements can then be attached.
In contrast to Camera Tracking (Matchmoving), which reconstructs the movement of the real camera, Object Tracking focuses on the movement of a single subject within the frame. Object Tracking is therefore a sub-discipline of the overarching Motion Tracking.
Distinction from Related Terms
| Method | What is Tracked | Typical Use |
|---|
| Object Tracking | Movement of a single object/point in the image | Attaching an element to a moving subject |
| Camera Tracking / Matchmoving | Movement of the real camera (3D scene) | Integrating CGI into a moving shot |
| 2D Tracking | Position in X/Y (flat plane) | Text overlays, screen replacements |
| 3D Tracking | Position including depth (X/Y/Z) | 3D models, perspective inserts |
Use in Post-Production
Object Tracking is used to attach image elements to a moving subject, for example, to fix text or graphics to a moving vehicle, to replace the content of a screen or sign, to remove logos, or to place a 3D object onto a moving surface with correct perspective. For simple 2D tasks, tracking in the image plane is sufficient; for depth-accurate inserts, 3D tracking is used.
Object Tracking is implemented using tools such as the point tracker in Adobe After Effects, planar trackers like Boris FX Mocha (Mocha AE / Mocha Pro), and matchmoving and compositing software like SynthEyes and Nuke. Planar and mesh-based methods can also track curved or organic surfaces.