<p>A combinatorial algorithm to construct the triangular convex skull of a hole-free <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\varvec{2}\)</EquationSource> </InlineEquation>-D digital object is presented in this paper. The object that is a finite subset of <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(\mathbb {Z}^{\varvec{2}}\)</EquationSource> </InlineEquation> is assumed to lie on a triangular grid and the proposed algorithm finds a maximal-area connected set of triangles of the triangular grid that is convex. To obtain the required skull, the inner triangle cover that tightly inscribes the given <InlineEquation ID="IEq3"> <EquationSource Format="TEX">\(\varvec{2}\)</EquationSource> </InlineEquation>-D digital object is constructed first. A traversal is then made along the inner triangular cover from the top-left vertex to construct the triangular convex skull. To maximize the total area of the triangular convex skull, a few combinatorial rules are formulated to exclude some portion of the inner triangular cover. The proposed algorithm is efficient as makes use of addition and comparison in the integer domain. The correctness of the algorithm is verified on various hole-free <InlineEquation ID="IEq4"> <EquationSource Format="TEX">\(\varvec{2}\)</EquationSource> </InlineEquation>-D digital objects and results are very promising. The proposed algorithm has the time complexity of <InlineEquation ID="IEq5"> <EquationSource Format="TEX">\(\varvec{O}\varvec{(n)}\)</EquationSource> </InlineEquation>, where <InlineEquation ID="IEq6"> <EquationSource Format="TEX">\(\varvec{n}\)</EquationSource> </InlineEquation> is the number of vertices of the inner triangular cover.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

A combinatorial algorithm to compute the triangular convex skull of a digital object

  • Md Abdul Aziz Al Aman,
  • Apurba Sarkar,
  • Mousumi Dutt,
  • Arindam Biswas

摘要

A combinatorial algorithm to construct the triangular convex skull of a hole-free \(\varvec{2}\) -D digital object is presented in this paper. The object that is a finite subset of \(\mathbb {Z}^{\varvec{2}}\) is assumed to lie on a triangular grid and the proposed algorithm finds a maximal-area connected set of triangles of the triangular grid that is convex. To obtain the required skull, the inner triangle cover that tightly inscribes the given \(\varvec{2}\) -D digital object is constructed first. A traversal is then made along the inner triangular cover from the top-left vertex to construct the triangular convex skull. To maximize the total area of the triangular convex skull, a few combinatorial rules are formulated to exclude some portion of the inner triangular cover. The proposed algorithm is efficient as makes use of addition and comparison in the integer domain. The correctness of the algorithm is verified on various hole-free \(\varvec{2}\) -D digital objects and results are very promising. The proposed algorithm has the time complexity of \(\varvec{O}\varvec{(n)}\) , where \(\varvec{n}\) is the number of vertices of the inner triangular cover.