%0 Conference Proceedings %T Trajectory Estimation for Exponential Parameterization and Different Samplings %+ Faculty of Applied Informatics and Mathematics %+ Department of Mathematics and Statistics %A Kozera, Ryszard %A Noakes, Lyle %A Szmielew, Piotr %Z Part 7: Algorithms %< avec comité de lecture %( Lecture Notes in Computer Science %B 12th International Conference on Information Systems and Industrial Management (CISIM) %C Krakow, Poland %Y Khalid Saeed %Y Rituparna Chaki %Y Agostino Cortesi %Y Sławomir Wierzchoń %I Springer %3 Computer Information Systems and Industrial Management %V LNCS-8104 %P 430-441 %8 2013-09-25 %D 2013 %R 10.1007/978-3-642-40925-7_40 %K Interpolation %K numerical analysis %K computer graphics and vision %Z Computer Science [cs] %Z Humanities and Social Sciences/Library and information sciencesConference papers %X This paper discusses the issue of fitting reduced data $Q_m=\{q_i\}_{i=0}^m$ with piecewise-quadratics to estimate an unknown curve γ in Euclidean space. The interpolation knots $\{t_i\}_{i=0}^m$ with γ(ti) = qi are assumed to be unknown. Such non-parametric interpolation commonly appears in computer graphics and vision, engineering and physics [1]. We analyze a special scheme aimed to supply the missing knots $\{\hat t_i^{\lambda}\}_{i=0}^m\approx\{t_i\}_{i=0}^m$ (with λ ∈ [0,1]) - the so-called exponential parameterization used in computer graphics for curve modeling. A blind uniform guess, for λ = 0 coupled with more-or-less uniform samplings yields a linear convergence order in trajectory estimation. In addition, for ε-uniform samplings (ε ≥ 0) and λ = 0 an extra acceleration αε(0) =  min {3,1 + 2ε} follows [2]. On the other hand, for λ = 1 cumulative chords render a cubic convergence order α(1) = 3 within a general class of admissible samplings [3]. A recent theoretical result [4] is that for λ ∈ [0,1) and more-or-less uniform samplings, sharp orders α(λ) = 1 eventuate. Thus no acceleration in α(λ) < α(1) = 3 prevails while λ ∈ [0,1). Finally, another recent result [5] proves that for all λ ∈ [0,1) and ε-uniform samplings, the respective accelerated orders αε(λ) =  min {3,1 + 2ε} are independent of λ. The latter extends the case of αε(λ = 0) = 1 + 2ε to all λ ∈ [0,1). We revisit here [4] and [5] and verify their sharpness experimentally. %G English %Z TC 8 %2 https://inria.hal.science/hal-01496089/document %2 https://inria.hal.science/hal-01496089/file/978-3-642-40925-7_40_Chapter.pdf %L hal-01496089 %U https://inria.hal.science/hal-01496089 %~ SHS %~ IFIP-LNCS %~ IFIP %~ IFIP-TC %~ IFIP-TC8 %~ IFIP-CISIM %~ IFIP-LNCS-8104