-wball x y z r f =
                Enhance automatic weight from '-useweight' by a factor
                of 1+f*Gaussian(FWHM=r) centered in the base image at
                DICOM coordinates (x,y,z) and with radius 'r'. The
                goal of this option is to try and make the alignment
                better in a specific part of the brain.
               * Example:  -wball 0 14 6 30 40
                 to emphasize the thalamic area (in MNI/Talairach space).
               * The 'r' parameter must be positive (in mm)!
               * The 'f' parameter must be between 1 and 100 (inclusive).
               * '-wball' does nothing if you input your own weight
                 with the '-weight' option :(
               * '-wball' does change the binary weight created by
                 the '-noweight' option.
               * You can only use '-wball' once in a run of 3dQwarp.
             *** The effect of '-wball' is not dramatic. The example
                 above makes the average brain image across a collection
                 of subjects a little sharper in the thalamic area, which
                 might have some small value. If you care enough about
                 alignment to use '-wball', then you should examine the
                 results from 3dQwarp for each subject, to see if the
                 alignments are good enough for your purposes.

 -wmask ws f  = Similar to '-wball', but here, you provide a dataset 'ws'
                that indicates where to increase the weight.
               * The 'ws' dataset must be on the same 3D grid as the base
                  dataset.
               * 'ws' is treated as a mask -- it only matters where it
                 is nonzero -- otherwise, the values inside are not used.
               * After 'ws' comes the factor 'f' by which to increase the
                 automatically computed weight. Where 'ws' is nonzero,
                 the weighting will be multiplied by (1+f).
               * As with '-wball', the factor 'f' should be between 1 and 100.
               * You cannot use '-wball' and '-wmask' together!