A system for separating a potential compound object representation into two or more representations of sub-objects in an image, comprising: a compound object splitter component configured to generate representations of two or more sub-objects from a representation of the potential compound object by eroding one or more layers of voxels from the representation of the potential compound object: and a volume reconstructor component configured to generate image data representing the two or more sub-objects having a combined volume approximate a volume of the representation of the potential compound object; and a compactness merger component configured to merge image data representing the at least two sub-objects, generated from eroding one or more layers of voxels from the representation of the potential compound object, into image data representing a single object based at least in part upon a determined compactness ratio being within a predetermined compactness threshold; wherein the compactness merger component comprises: an Eigen-box generator component configured to generate an Eigen-box for the image data representing the respective distinct at least two sub-objects and for a union of the image data representing the at least two sub-objects; a fill ratio determiner component configured to calculate an Eigen-box fill ratio for an object in an Eigen-box by calculating how much the object fills the Eigen-box; and a compactness ratio generator component configured to generate the compactness ratio by comparing Eigen-box fill ratios of the image data representing the respective at least two sub-objects to an Eigen-box fill ratio of the union of the image data representing the at least two sub-objects. a compound object splitter component configured to generate representations of two or more sub-objects from a representation of the potential compound object by eroding one or more layers of voxels from the representation of the potential compound object: and a volume reconstructor component configured to generate image data representing the two or more sub-objects having a combined volume approximate a volume of the representation of the potential compound object; and a compactness merger component configured to merge image data representing the at least two sub-objects, generated from eroding one or more layers of voxels from the representation of the potential compound object, into image data representing a single object based at least in part upon a determined compactness ratio being within a predetermined compactness threshold; wherein the compactness merger component comprises: an Eigen-box generator component configured to generate an Eigen-box for the image data representing the respective distinct at least two sub-objects and for a union of the image data representing the at least two sub-objects; a fill ratio determiner component configured to calculate an Eigen-box fill ratio for an object in an Eigen-box by calculating how much the object fills the Eigen-box; and a compactness ratio generator component configured to generate the compactness ratio by comparing Eigen-box fill ratios of the image data representing the respective at least two sub-objects to an Eigen-box fill ratio of the union of the image data representing the at least two sub-objects. an Eigen-box generator component configured to generate an Eigen-box for the image data representing the respective distinct at least two sub-objects and for a union of the image data representing the at least two sub-objects; a fill ratio determiner component configured to calculate an Eigen-box fill ratio for an object in an Eigen-box by calculating how much the object fills the Eigen-box; and a compactness ratio generator component configured to generate the compactness ratio by comparing Eigen-box fill ratios of the image data representing the respective at least two sub-objects to an Eigen-box fill ratio of the union of the image data representing the at least two sub-objects.