Algorithms for the recovery of 3D objects from 2D line drawings
Fen Fang · 2014
Reconstructing the 3D object depicted in a line drawing consistent with human perception is an interesting and important topic in computer vision.Normally, the reconstruction process requires two main steps: topological analysis and 3D recovery.This thesis makes three novel contributions in the three steps: (1) Decomposition of the line drawing of a complex object into a collection of drawings of simple manifolds; (2) Finding the faces of the object in the drawing; (3) Reconstruction of the object in both parallel and perspective projections.The work here is restricted to drawings of planar polyhedra.The decomposition of a complex line drawing into drawings of simpler manifolds occurs at (1) non-manifold vertices, (2) along non-manifold edges and (3) across internal faces.The algorithms for the first two are simple.The decomposition across an internal face has two stages: basic decomposition and the subsequent repair.Our results show that the algorithm can deal with objects with planar faces.Reconstructing of the 3D object is much easier and much more efficient from a simpler drawing than a complex one.Knowing the faces of the object in a drawing is essential to the 3D reconstruction of the object.A new face finding algorithm much more efficient than the existing ones is presented here.This algorithm also contains two stages: decomposition and face forming.In the first stage, a line drawing is decomposed into sub-loops, which are connected but usually open sequence of edges that must belong to the same face.Faces are formed from the sub-loops in the next stage.The method has the capability to differentiate an internal face from a real one once it is formed.