**fScan Reference Manual, Chapter 2 (CmdLineOptions:Expr): Dilate**
===== Dilate -- Expand an intensity region in a 3D image volume =====
 **usage:  -expr dilate val maskbits newval flag nmatch nneighbors**\\

  * VAL - "Inside" value (or Percent value if (FLAG & (4|8))
  * MASKBITS - voxel data values to consider for comparing with VAL (DATABITS is inverse of MASKBITS)
  * NEWVAL - bit-value to turn on when adding (dilating) a voxel\\
    * If NEWVAL is negative and MASKBITS is zero, then neighboring data voxel values will be used when dilating into "empty" voxels.

  * FLAG:
    * 0 - (default)
    * 2 - Erode/dilate in 2-D plane only
    * 4 - Stop on dark edge (voxel darker than (100-VAL)% of inside neighbors (Needs MASKBITS set)
    * 8 - Stop on bright edge (brighter than (100+VAL)% of inside neighbors
    * 16 - Dilate all non-zero values except VAL (useful for filling in around VAL areas)
  * NMATCH - number of adjacent voxels matching criterion needed for dilation (default=1)
  * NNEIGHBORS - number of neighboring voxels to consider (default=26 if 3D, 8 if 2D)

If MASKBITS is non-zero, it is used to mask both the input data values and NEWVAL; only those data bits are considered during comparisons and only the NEWVAL bits are changed during dilation.

**See Also:**\\
[[jvs:fscan:manual:chapter2:expression:erode|ERODE]],
[[jvs:fscan:manual:chapter2:expression:flood|FLOOD]],

[[jvs:fscan|fScan Home]], 
[[jvs:fscan:manual|fScan Manual]], 
[[jvs:fscan:manual:chapter2|CmdLineOptions]], 
[[jvs:fscan:manual:chapter2:expression|Expression Command]], 
[[jvs:fscan:manual:help|Manual Help]]