In this work we propose a method for the polygonization of octree-based reconstructions by dual contouring. Dual contouring is an adaptive method for determining contiguous polygonal meshes from signed octrees. It determines the positioning of the vertices of the mesh by minimizing a quadratic error expressed in terms of hermitian data. In order to apply dual contouring on volumetric reconstruction from silhouettes we devised a method that is able to determine the discrete topology of the contour in relation to the octree cells, as well as the hermitian data corresponding to the intersections and normals of conic volumes whose intersection approximates a structure known as Visual Hull. Due to the discrete and extremely noisy nature of the data used in the reconstruction we had to devise a different criterion for mesh simplification that applies topological consistency tests only when the geometric error measure is beyond a given tolerance. We present results of the application of the proposed method in the extraction of a mesh corresponding to the surface of objects of a real scene.