The key to reconstruction is to identify which part of the occluded region can potentially be connected behind the occlusion.
To reconstruct occluded areas is a difficult task since we need to estimate something which is not visible. Sometime it is in fact impossible to reconstruct occluded areas, such as the case when the hidden area contains abrupt surface changes which do not follow the concept of continuous constraints. This explains why we propose a conservative approach to the reconstruction. We need to be sure we see the right condition allowing some reconstructions.