The Research On Pieces Of Bronze Relics Virtual Stitching Technology And Geometric Feature Extraction

There is a considerable amount of bronze ware unearthed from the damaged situation because of its age.Using the computer aided fragments virtual stitching is the one of the key technology of protection and digital processing of bronze relics.For bronze ware is non rigid body,and the structure or texture characteristics of fragments are often not obvious,which lead to the difficult of model matching.Therefore,the researches on pieces of bronze relics virtual stitching technology are as follows:(1)Bronze pieces classification splicing was put forward.Based on the characteristics of the bronze ware thin-wall pieces of cultural relics,it can be divided into 2d and 3d fragments according to whether it has obvious characteristics of three dimensional and its size.And the subsequent stitching also need the classification,namely,respectively matching in the two-dimensional plane and three-dimensional space.(2)An approach of virtual small bronze fragments reassembly based on curvature feature was proposed.First,we extract and smooth the 2d contour of small bronze fragment,and then compute the curvature of each point on the contour and regard the local maxima of curvature as the candidate corners.After that,the round corners and false corners are eliminated according to the region of support.And then the chord lengths between the adjacent corners are calculated as the feature sequences to find the match.Finally,the reassembled result is obtained and refined by applying the invariance of the vector module.The experiment result proves that the method can effectively improve the efficiency of stitching and the effect of matching.(3)A virtual stitching method of 3D bronze fragments was proposed based on principal component analysis and fast Fourier transform.The contour was represented for the curve segment.Each curve segment was transformed into a local coordinate system which was established by the principal component analysis(PCA),and then projected onto two coordinate plane.Extract the characteristic function of projection results respectively,andcalculate the Fourier energy difference of the characteristic function as the criterion for the coarse match results.Then,the curves of two fragments were transformed into their local coordinate system based on the coarse matching transformation matrix and the curve length of the third public projection plane was measured to the elaboration matching,and matching results were achieved.(4)The bronze relics geometric feature size extraction system was designed and developed.The system is easy to operate.It can quickly extract bronze geometry characteristic information,including the diameter,bottom diameter,height,etc.,to provide reliable data for subsequent artificial restoration of bronze ware.