brede_vol_abs - Absolute value of voxel values
Vout = brede_vol_abs(Vin)
Input: Vin 'Vol' structure
Output: Vout 'Vol' structure
Return the input volume with voxels converted to their
absolute values.
See also BREDE, BREDE_VOL, BREDE_VOL_THRESHOLD,
BREDE_MAT_ABS.
$Id: brede_vol_abs.m,v 1.1 2005/10/19 13:07:06 fnielsen Exp $