Calibrating the camera

In MatchMover, a camera is characterized by its internal parameters such as Principal Point, Focal Length, Pixel Aspect Ratio, and Distortion. In some cases, you may already have information about the camera. For example, you may know that it is a 24 ×36 mm film back camera with a 35 mm lens. You can then input this information into MatchMover before launching the camera tracker. For this lesson, you will calibrate the camera using MatchMover's default values. This process of calibrating a camera involves reconstructing the 3D points corresponding to the 2D tracks and computing the camera path for all the sequences or frames and all the objects in one solve.

NoteYou can bypass this section of the lesson by openningShot_solved.mmf. This file can be found in the Tutorials/Supervised_Shot directory. You can then proceed to Creating a coordinate system.

To calibrate the camera

Run the calibration by selecting 3D Tracking > Solve For Camera or by clicking the Solve For Camera icon.
The camera is calibrated.
Click the 3D space icon that is located in the top left of the Workspace view.
The view switches to 3D mode and the tracks are now displayed as 3D cones rather than cross-hairs. A camera icon is placed in the Workspace, which represents the camera you calibrated.
Select View > Lock On Camera or click the Lock on Camera icon.
Play the sequence to check the tracking.
Notice the image sequence plays back from the perspective of the camera.