1. A computer-implemented method of labeling components comprising the steps of: labeling with a current label all object voxels that are internal to a predetermined sub-volume oriented with respect to an unlabeled object voxel, and directly connected to the unlabeled object voxel; repeating the labeling step for all object 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; wherein said labeling step comprises a combination of iterative and recursive processes.