Table 4.

Comparison of the transformation errors and Procrustes distance between the DVFs without penalty and with the rigidity penalties.

	Intensity-based	Orthonormality-based	Distance-preserving
Translation (mm)
Mean magnitude	(0.34, 0.13, 0.38)	(0.14, 0.11, 0.37)	(0.11, 0.11, 0.36)
Standard deviation	(0.41, 0.16, 0.32)	(0.16, 0.13, 0.25)	(0.13, 0.13, 0.25)
Rotation (deg)
Mean magnitude	(1.22, 0.50, 0.61)	(0.65, 0.32, 0.33)	(0.58, 0.34, 0.28)
Standard deviation	(1.32, 0.62, 0.84)	(0.69, 0.40, 0.42)	(0.70, 0.45, 0.35)
Procrustes distance (mm)	0.53 (0.11)	0.28 (0.04)	0.11 (0.03)