Illustration of the principle of epipolar geometry in stereo correspondence. In order to calculate the 3D location of a point P three steps are needed: (1) Identify the pixel coordinates of P in Camera 1 (P1), (2) search the image of Camera 2 to find the corresponding pixel coordinate of P image 2 (P2) and (3) project and compute the 3D location of P from the coordinates of P1, P2, and the known camera geometry. Epipoles (e1 and e2) are defined at the intersection of each image plane and the vector between the camera centers. The epipolar plane is the plane containing the camera centers and point P. The search for the correspondence pixel P2 can be limited to the line created by the intersection of the epipolar plane and the image plane of Camera 2. Sensor systems that restrict correspondence search to the epipolar lines can exhibit “ghosting” of features along the reduced search vector due to correspondence uncertainty (Ref. 49).
Thermal drift and reproducibility measured using a commercially available infrared camera system. (a) Thermal drift: Measurement of 3D displacement of a fixed target due to camera drift from initial startup monitored for 100 min. (b) Reproducibility: Measurement of 3D displacement of a fixed target with multiple readings. Vertical axis is the absolute location reading (mm) for a fixed target and the horizontal axis are multiple readings. The displacements in this example vary between 0.01 and 0.04 mm.
Tracking report while moving a phantom 1 cm in each of the three orthogonal directions.
Currently available localization systems covered in this report.
Recommended QA and frequency.
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