User manual

85XX Series Network DVR User Manual……………………………………………………………………….V1.0
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4.4.2.10 Calibrating a Camera
Calibrating a camera is necessary in order to estimate object parameters such as height, area, speed and
classification. If you know the height, tilt angle and vertical field of view corresponding to your installation, you
can simply type the parameters in the appropriate boxes and apply the changes.
If however, you do not know, or are unable to find out the camera parameters, this topic provides a
step-by-step guide to calibrating a camera.
Step 1: Find some people in the scene
Find some people, or some people-sized objects in the scene. Try to find a person near the camera, and a
person further away from the camera. It is useful to use the Video Control button to pause the video so that the
mimics can be accurately placed. Place the mimics on top of or near the people. Enter in the known height or
estimated height.
Step 2: Adjust tilt angle and camera height
Now, adjust the camera tilt angle and vertical field of view until both mimics are approximately the same size
as a real person at that position in the scene. If an estimated height is entered then adjust this along with the
other two parameters.
Click and drag the ground plane to change the tilt angle, use the mouse wheel to adjust the camera height and
drag the slider to change the vertical field of view. The 3 calibration parameters will be reflected in the edit
boxes in the Camera Setup section of the web page.
Apply the changes: