appear in the image. The red area is for counting. To increase the success rate of the manual
calibration, make sure the lens height is the true value in vertical direction between the lens and
the ground.
Auto Calibration Mode: It will generate the lens height and a green calibration area automatically.
The calibration area is used for calibrating the height from the ground to lens. So we strongly
recommend to select the totally ground part as calibration area.
