An Active Vision Approach to Height Estimation with Optical Flow

In this research we propose a prudent method for estimating the principal point of a camera with a means of active vision and, in particular, by varying the focal length of a camera and applying optical flow with the aim to estimate the height of the objects. In our method only one parameter is known, namely the height of the camera from the ground. No reference objects or points are used in the real environment nor any calibration of the camera has been employed. The known camera height is projected in the image plane, that is, from the principal point to the ground and is used as a reference to estimate the height of objects. Our results show that our method for estimating both the principal point and the height of the objects is parsimonious yet effective.