Full Resolution Femur sample:
Run the registration Using URAL, default parameters, Subsample=8,with Finetune=1.
Timings:
Primitive generation:   3 min
AutoFocus:                  50 sec
FineTune:                     25 sec

Result is below.  I don't see a need to change anything about the registration FineTune.
MI problem has to be investigated.

Femur Full-resolution registration sample:

URAL registration works well with the present default parameters. Below is the result for the AutoFocus stage (no Finetune)

Using URAL, AutoFocus-only, no Finetune

However, for the MutualInfo this stage fails with the result grossly misplaced.

FGT segmentation: Implemented a hybrid FAT thresholding method based on Z-alg for when histogram has 2 distinct peaks. New criteria was developed for the absence of such peaks. In that case the PVV segmentation is invoked.
Processed all the 16 "challenge" cases with good results.