Program-Method Average X FRE Average Y FRE FRE Norm
No Registration 4.66 8.06 9.31
MIPAV - CR 1.58 1.10 1.93
MIPAV - NCC 1.43 1.05 1.77
MIPAV - NMI 2.19 0.61 2.27
FLIRT - CR 1.70 0.94 1.94
FLIRT - NCC 1.11 0.93 1.45
FLIRT – MI 1.69 1.09 2.01
FLIRT - NMI 2.02 1.30 2.40
AIR - Woods 10.75 1.10 10.81
MAR-GUI 1.13 0.76 1.36
Table 2: Fiducial registration error (FRE) results in units of mm. The methods of registration are as follows: correlation ratio (CR), normalized cross correlation (NCC), mutual information (MI), normalized mutual information (NMI), and the Woods algorithm (Woods). The FRE is calculated for each fiducial and averaged for each axis. The final column is the Euclidean norm of the average x and y FRE.