We propose a skull completion framework based on symmetry and surface matching. To obtain reliable symmetry detection on incomplete models, we define a local shape signature consisting of the principle curvature (encoding bending of the surface) and the shape diameter function (encoding volume of the model). Symmetric regions on the skull are used to repair the damages. For big missing regions across both sides of the symmetric plane, we use a template-based completion approach, which first maps the template to the damaged skull, then transplants the region on the template to fill holes. Our proposed completion framework will iteratively conduct symmetry-based and template-based repairs; this significantly improves the completion accuracy and robustness. Several damaged skulls have been repaired successfully in our framework. This skull completion framework will greatly benefit subsequent archeological and anthropological processing and analysis.
We present an effective completion system for fragmented and damaged skulls. The purpose of this work is to provide an as-accurate-as-possible complete skull model for subsequent forensic or archeological tasks such as facial reconstruction. The proposed assembly and completion algorithms may also be used to repair other fragmented objects with inherent symmetry. A two-step assembly framework is proposed: (1) rough assembly by an ICP-like template matching algorithm integrated with the slippage features and spin-image descriptors; (2) assembly refinement by a global optimization on least square transformation error (LSTE) of break-curves. After the assembly process, a symmetry-based completion framework is used for skull completion. Damaged regions will be repaired using their symmetric patches on the skull; if both sides are missing, patches from the template will be transplanted/deformed to fill the damaged regions. Experiments on the repair of several sets of real skull fragments demonstrate the efficacy and robustness of this framework.
