Measuring length and girth of a tubular shape by quasi-helixes

• A formal definition, as well as a set of practical algorithms for quasi-helixes, is presented.
• The use in measuring length and girth and graphical comparison with feature aligned methods are discussed.
• Applying helical curves to vector field design.

Length and girth are central to measure the size of tube shaped objects. This paper extends circular helical curves to general tubular shapes and proposes a novel method for measuring their length and girth. We call the extended circular helixes quasi-helical curves. A formal definition, as well as a set of practical algorithms for quasi-helixes, is presented in this paper. Experimental results demonstrate that our method is fast, intrinsic, insensitive to noises, invariant to triangulation and resolution. Furthermore, quasi-helical curves can also be used in classifying 3D shapes and designing vector fields on surfaces of revolution.

A circular helix and a quasi-helical curve.Figure optionsDownload high-quality image (140 K)Download as PowerPoint slide