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arXiv · 1411.4627

Ellipse-preserving Hermite interpolation and subdivision

Costanza Conti·Lucia Romani·Michael Unser
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Abstract

We introduce a family of piecewise-exponential functions that have the Hermite interpolation property. Our design is motivated by the search for an effective scheme for the joint interpolation of points and associated tangents on a curve with the ability to perfectly reproduce ellipses. We prove that the proposed Hermite functions form a Riesz basis and that they reproduce prescribed exponential polynomials. We present a method based on Green's functions to unravel their multi-resolution and approximation-theoretic properties. Finally, we derive the corresponding vector and scalar subdivision schemes, which lend themselves to a fast implementation. The proposed vector scheme is interpolatory and level-dependent, but its asymptotic behaviour is the same as the classical cubic Hermite spline algorithm. The same convergence properties---i.e., fourth order of approximation---are hence ensured.

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Costanza Conti, Lucia Romani, Michael Unser. 2014-11-17. Ellipse-preserving Hermite interpolation and subdivision. https://arxiv.org/abs/1411.4627

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