1. A method of labeling components comprising the steps of: labeling with a current label all voxels that are internal to a predetermined sub-volume oriented with respect to an unlabeled voxel, and directly connected to the unmarked voxel; repeating the labeling step for all voxels that are not internal to the predetermined sub-volume, but which are labeled with a current label; increasing a window size to a predetermined maximum; incrementing the current label; and repeating the preceding steps for remaining unlabeled object voxels.