Contents
Why are the track points on the 3D camera different?
Note that the track points are of different sizes, indicating that the 3D Camera Tracker was able to derive depth information from the scene and correctly place the track points at different distances from the camera. The smaller a track point appears, the further away it is from the camera.
How to calculate the distance from camera to subject?
To calculate the distance from camera to subject, use Pythagorus’ Theorem: a² + b² = c² Although a single camera will provide an overall view of a scene, it might not provide enough detail to identify individuals. If this is one of the surveillance goals, then an additional camera can be included in the design (see below).
What’s the best angle to place a camera?
When placing a cameras by a door or in a lobby, care should be taken to avoid placement at too high an angle. As seen here, the greater the angle, the more difficult it is to see facial features. In our example, an angle of 10-15° gives the best view for facial identification.
Why is camera placement important for a PTZ camera?
Lighting (and backlighting), angles, reflections, dead zones, and the zoom factor for PTZ cameras are all matters to consider. Sometimes, it’s actually easier to change the environment itself, for example by shading windows or moving objects to new locations. Camera placement is also an important factor in deterring vandalism.
How does a 3D camera tracker work in Photoshop?
The tracker will try to find as many features as possible in your footage and track their movement from frame to frame. This generates a cloud of 2 dimensional track points on your footage. Using this cloud of 2D track points, the 3D Camera Tracker then tries to ‘solve the camera’.
Are there any problems with the 3D camera tracker?
As great as the 3D Camera Tracker is, there are a number of common problems that people encounter when trying to track their footage and this tutorial will explain what is going wrong and how you can fix it. Before we look into why the 3D camera tracker does not work, we first need to understand how it does work.
How many frames does a video need to play at 24 fps?
As an example a short video at 24 fps needs 2763 frames to play. By changing the frame rate to 25 fps the video remains at 2763 frames but the audio length extends to 2879 frames to maintain the same length in seconds.