Biomedical Engineering Reference
In-Depth Information
0.14
SD
0.12
SD
0.1
0.08
CE
RCE
CE
0.06
RCE
0.04
0.02
0
−
15
−
10
−
5
0
5
10
15
Y Translation (mm)
Figure 10.15:
The cross-entropy (CE), reversed cross-entropy (RCE), and sym-
metric divergence (SD) profiles (with a likely priori) of an MR/Em image
pair in the vicinity of a manual registration when the y-translation changes
independently.
and different strategies to handle the zero joint pdfs are compared. The profiles
are labeled in the same manner as was used for the cross-entropy minimization
case. All of the resultant profiles are similar. Again, we elected to ignore the zero
pdf terms since the corresponding profiles are relatively smooth and worked
well in practice.
Since the symmetric divergence measure has cross-entropy and reversed
cross-entropy components, the issues with numerical stability were addressed
in a similar manner.
10.6
Concluding Remarks
We have applied the information-theoretic measures cross-entropy, reversed
cross-entropy, and symmetric divergence to retrospective three-dimensional
