We imaged the pin head 50 times at different viewing angles and locations within the entire image FOV and derived the world coordinates
of the pin head from different views and calibration matrix combinations.
We propose a novel eye tracking method that can estimate 3D world coordinates
using an infrared (IR) stereo camera for indoor and outdoor environments.
In Figure 2(a), there are three coordinate systems: world coordinates
east, north, uP (ENU), camera coordinates (xyz), and image coordinates (uv).
The extrinsic parameters contain information about the position and orientation of a frame attached to the points in the world coordinates
where [[[mu]' v' 1].sup.T] and [[X Y Z 1].sup.T] are the image and world coordinates
, respectively, corresponding to the homogeneous coordinates; s is a scaling factor; [[r.sub.1] [r.sub.2] [r.sub.3] t] is the external parameter matrix, converting between real and camera coordinates, where [[r.sub.1] [r.sub.2] [r.sub.3]] is the rotation matrix and t is the world coordinate
origin in camera centric coordinates; and A is the internal parameter matrix:
In hypothesis generating process, we can obtain candidate target distance, angle, speed, and other pieces of information by radar and then get the world coordinates
of the candidate target, on the basis of an inverse, the camera calibration principle; we obtain conversions relationship between the world coordinates
and image pixel coordinates, initially identified region of candidate targets on the image, namely, the region of interest (ROI).
From this the real world coordinates
of the laser line can be calculated:
 extracted the left-turning vehicles trajectories data using the video method and proposed a translating method of the image coordinates and the world coordinates
. Kyte et al.
Thirdly, choose a camera as a reference one and wrap the view to overhead view according to the world coordinates
of ground control points (GCPs) and corresponding image coordinates.
Since the homography matrix [H.sub.i] have been calibrated based on (4) by using the points in area of 300x300 pixels, the world coordinates
of corner points in nine patterns can be projected onto the pixel coordinates.
This point is now available in world coordinates
(x, y) and corresponds to the shown in the image representing the bird view extraction.