Assessment of Iterative Closest Point Registration Accuracy for Different Phantom Surfaces Captured by an Optical 3D Sensor in Radiotherapy

Table 3

Overall assessment of the tested ICP algorithms.

Property	Algorithm
	Wilm	Kroon	Renoald	Bergström	AlignRT
Closest point search	kd-tree	Full	Full	Full
Weighting	None	None	None	Distance-based
Rejection	None	None	None	None
Error metric	Point-to-plane	Point-to-point	Point-to-point	Point-to-point	Point-to-plane
Minimization	Linearization of rotation matrix	Global search	SVD	Levenberg-Marquardt
Speed^b	+	−	++	− −	+
Max.	<1.0 mm	>1.0 mm	>1.0 mm	>1.0 mm	<1.0 mm
Max.	>0.5°	<0.5°	<0.5°	<0.5°	>0.5°

^aUnknown.
^b++: very fast; +: fast; −: slow; − −: very slow.