Special curves in the Minkowski space such as Minkowski Pythagorean hodograph curves play an important role in computer-aided geometric design,and their usages are thoroughly studied in recent years.Bizzarri et al.(20...Special curves in the Minkowski space such as Minkowski Pythagorean hodograph curves play an important role in computer-aided geometric design,and their usages are thoroughly studied in recent years.Bizzarri et al.(2016)introduced the class of Rational Envelope(RE)curves,and an interpolation method for G1 Hermite data was presented,where the resulting RE curve yielded a rational boundary for the represented domain.We now propose a new application area for RE curves:skinning of a discrete set of input circles.We show that if we do not choose the Hermite data correctly for interpolation,then the resulting RE curves are not suitable for skinning.We introduce a novel approach so that the obtained envelope curves touch each circle at previously defined points of contact.Thus,we overcome those problematic scenarios in which the location of touching points would not be appropriate for skinning purposes.A significant advantage of our proposed method lies in the efficiency of trimming offsets of boundaries,which is highly beneficial in computer numerical control machining.展开更多
An important aim in pattern recognition is to cluster the given shapes. This paper presents a shape recognition and retrieval algorithm. The algorithm first extracts the skeletal features using the medial axis transfo...An important aim in pattern recognition is to cluster the given shapes. This paper presents a shape recognition and retrieval algorithm. The algorithm first extracts the skeletal features using the medial axis transform. Then, the features are transformed into a string of symbols with the similarity among those symbols computed based on the edit distance. Finally, the shapes are identified using dynamic programming. Two public datasets are analyzed to demonstrate that the present approach is better than previous approaches.展开更多
基金supported by the construction EFOP-3.6.3-VEKOP-16-2017-00002supported by the European Union,co-financed by the European Social FundOpen access funding was provided by University of Debrecen。
文摘Special curves in the Minkowski space such as Minkowski Pythagorean hodograph curves play an important role in computer-aided geometric design,and their usages are thoroughly studied in recent years.Bizzarri et al.(2016)introduced the class of Rational Envelope(RE)curves,and an interpolation method for G1 Hermite data was presented,where the resulting RE curve yielded a rational boundary for the represented domain.We now propose a new application area for RE curves:skinning of a discrete set of input circles.We show that if we do not choose the Hermite data correctly for interpolation,then the resulting RE curves are not suitable for skinning.We introduce a novel approach so that the obtained envelope curves touch each circle at previously defined points of contact.Thus,we overcome those problematic scenarios in which the location of touching points would not be appropriate for skinning purposes.A significant advantage of our proposed method lies in the efficiency of trimming offsets of boundaries,which is highly beneficial in computer numerical control machining.
基金Supported by the National Natural Science Foundation of China (No.60772121)the Natural Science Foundation of Anhui Provincial Education Department (No.KJ2008B024)
文摘An important aim in pattern recognition is to cluster the given shapes. This paper presents a shape recognition and retrieval algorithm. The algorithm first extracts the skeletal features using the medial axis transform. Then, the features are transformed into a string of symbols with the similarity among those symbols computed based on the edit distance. Finally, the shapes are identified using dynamic programming. Two public datasets are analyzed to demonstrate that the present approach is better than previous approaches.
