Biomedical Engineering Reference
In-Depth Information
2.6
2.4
1000
0
2.2
2
1.8
100
1.6
1.4
1
1.2
1
ignored
0.8
0.6
−
15
−
10
−
5
0
5
10
15
X Translation (mm)
Figure 10.10: The reversed cross-entropy profiles of an MR/Em image pair in
the vicinity of a manual registration when the x-translation changes indepen-
dently. The numbers adjacent to the profiles indicate the
α
value used to com-
pute a small probability value which is used to replace zero pdfs. Ignored means
that those pdfs are ignored when computing the profile.
most 1.01. The upper bound can be achieved only when there is 1 nonzero pdf
which is 1, and all other pdfs are zero. Based on these observations, we chose
α
=
100 in our calculation.
10.5.2
Registration by Cross-Entropy,
Reversed Cross-Entropy, and Symmetric
Divergence Minimization
10.5.2.1
Registration Performance
The standard deviations of four independent manual registration results were,
in vector form, (3.48, 0.53, 3.11, 1.68, 2.98, 1.83). The likely priori was calculated
