Table 2.

Pros and cons of using passive camera and active ToF camera in motion estimation.

	Passive Camera	Active ToF Camera
pros	Less expensive in price Studied for years and with many CV algorithm Relatively high resolution	Strong resilience to ambient light Sense depth infomation without post-processing
cons	Fail in poor/changing lighting conditions Need initialization process to recover the depth	Limit sensing distance (less than 10 m) Current CV algorithm can not used on the NIR image Relatively low resolution