Academia.edu no longer supports Internet Explorer.
To browse Academia.edu and the wider internet faster and more securely, please take a few seconds to upgrade your browser.
2008
In this report, we define simploidal polynomial functions and simploidal Bernstein bases, which are a generalization of the polynomials and Bernstein bases used in simplicial and tensorial Bézier patches. We then provide formulas for converting between simploidal polynomials expressed in various kinds of simploidal Bernstein bases.
Applied Mathematics and Computation, 2011
Explicit formulae for the Bézier coefficients of the constrained dual Bernstein basis polynomials are derived in terms of the Hahn orthogonal polynomials. Using difference properties of the latter polynomials, efficient recursive scheme is obtained to compute these coefficients. Applications of this result to some problems of CAGD is discussed.
Computers & Mathematics with Applications, 1995
This paper discusses the criteria of convexity, monotonicity, and positivity of Bernstein-B~zier polynomials over simplexes.
Journal of Approximation Theory, 2006
Here we give a simple proof of a new representation for orthogonal polynomials over triangular domains which overcomes the need to make symmetry destroying choices to obtain an orthogonal basis for polynomials of fixed degree by employing redundancy. A formula valid for simplices with Jacobi weights is given, and we exhibit its symmetries by using the Bernstein-Bézier form. From it we obtain the matrix representing the orthogonal projection onto the space of orthogonal polynomials of fixed degree with respect to the Bernstein basis. The entries of this projection matrix are given explicitly by a multivariate analogue of the 3 F 2 hypergeometric function. Along the way we show that a polynomial is a Jacobi polynomial if and only if its Bernstein basis coefficients are a Hahn polynomial. We then discuss the application of these results to surface smoothing problems under linear constraints.
Journal of Approximation Theory, 2012
We introduce a new variant of the blossom, the q-blossom, by altering the diagonal property of the standard blossom. This q-blossom is specifically adapted to developing identities and algorithms for q-Bernstein bases and q-Bézier curves over arbitrary intervals. By applying the q-blossom, we generate several new identities including an explicit formula representing the monomials in terms of the q-Bernstein basis functions and a q-variant of Marsden's identity. We also derive for each q-Bézier curve of degree n, a collection of n! new, affine invariant, recursive evaluation algorithms. Using two of these new recursive evaluation algorithms, we construct a recursive subdivision algorithm for q-Bézier curves.
International Journal of Mathematics, 2016
This paper provides an explicit closed form of generalized Jacobi–Koornwinder’s polynomials of degree [Formula: see text] in terms of the Bernstein basis of fixed degree [Formula: see text] Moreover, explicit forms of generalized Jacobi–Koornwinder’s type and Bernstein polynomials bases transformations are considered.
In this paper, we construct generalized Tschebyscheff-type weighted orthogonal polynomials in the Bernstein-Bezer form over the simplicial domain. We show that ..., form an orthogonal system over a triangular domain with respect to the generalized weight function
Honam Mathematical Journal, 2011
We prove two identities for multivariate Bernstein polynomials on simplex, which are considered on a pointwise. In this paper, we study good approximations of Bernstein polynomials for every continuous functions on simplex and the higher dimensional q-analogues of Bernstein polynomials on simplex.
Let Bm(f ) be the Bernstein polynomial of degree m. The generalized Bernstein polynomials
2017
Curve and surface intersection finding is a fundamental problem in computer-aided geometric design (CAGD). This practical problem motivates the undertaken study into methods for computing the square-free factorisation of univariate and bivariate polynomials in Bernstein form. It will be shown how these two problems are intrinsically linked and how finding univariate polynomial roots and bivariate polynomial factors is equivalent to finding curve and surface intersection points. The multiplicities of a polynomial’s factors are maintained through the use of a square free factorisation algorithm and this is analogous to the maintenance of smooth intersections between curves and surfaces, an important property in curve and surface design. Several aspects of the univariate and bivariate polynomial factorisation problem will be considered. This thesis examines the structure of the greatest common divisor (GCD) problem within the context of the square-free factorisation problem. It is show...
Computers & Mathematics with Applications, 2011
A new class of bivariate bases for the triangular surface construction, based on quadratic and cubic bivariate Bernstein polynomials, is proposed, by extending a model for the univariate basis with linear complexity. This new basis is recursively expressed by its recurrence formulae which are provided, and its important geometric properties are also described. In addition, a recursive algorithm for calculating a point on this triangular surface is recursively defined in the same manner as in the well known de Casteljau algorithm. The main advantage of this model is its recursive algorithm that is proven to construct a triangular surface of degree n in quadratic computational complexity, O(n 2 ).
Journal of Computational and Applied Mathematics, 1994
In this paper a new algorithm for generating values of Bernstein-Bezier polynomials is proposed and investigated. Opposite to the known algorithms, its computational complexity does not depend on the degree of a calculated polynomial. However, it allows to calculate only approximate values of the polynomial. These features allow to recommend the proposed algorithm for solving curve fitting and image processing problems in which processing a large number of data is necessary. The proposed method is based on a probabilistic interpretation of Bernstein-Bezier (BB-) polynomials and its properties are investigated in the statistical language. As a byproduct, a local nature of BB-polynomial approximation is displayed.
We construct multiple representations relative to different bases of the generalized Tschebyscheff polynomials of second kind. Also, we provide an explicit closed from of The generalized Polynomials of degree r less than or equal n in terms of the Bernstein basis of fixed degree n. In addition, we create the change-of-basis matrices between the generalized Tschebyscheff of the second kind polynomial basis and Bernstein polynomial basis
Graphics Gems, 1994
Journal of Approximation Theory, 2006
The evaluation of multivariate polynomials of n variables in Bernstein-Bézier form is considered. A forward error analysis for the corresponding de Casteljau algorithm and the VS algorithm is performed. We also include algorithms that simultaneously evaluate the polynomial and provide "a posteriori" error bounds, without increasing significantly the computational cost. The sharpness of our running error bounds is shown in the case of trivariate polynomials.
Computer Aided Geometric Design
A new variant of the blossom, the h-blossom, is introduced by altering the diagonal property of the standard blossom. The significance of the h-blossom is that the h-blossom satisfies a dual functional property for h-Bézier curves over arbitrary intervals. Using the h-blossom, several new identities involving the h-Bernstein bases are developed including an h-variant of Marsden's identity. In addition, for each h-Bézier curve of degree n, a collection of n! new, affine invariant, recursive evaluation algorithms are derived. Using two of these recursive evaluation algorithms, a recursive subdivision procedure for h-Bézier curves is constructed. Starting from the original control polygon of an h-Bézier curve, this subdivision procedure generates a sequence of control polygons that converges rapidly to the original h-Bézier curve.
arXiv (Cornell University), 2015
We construct multiple representations relative to different bases of the generalized Tschebyscheff polynomials of second kind. Also, we provide an explicit closed from of The generalized Polynomials of degree r less than or equal n in terms of the Bernstein basis of fixed degree n. In addition, we create the change-of-basis matrices between the generalized Tschebyscheff of the second kind polynomial basis and Bernstein polynomial basis.
Journal of Mathematical Analysis and Applications, 2007
Explicit formulae, in terms of Bernstein-Bézier coefficients, of the Fourier transform of bivariate polynomials on a triangle and univariate polynomials on an interval are derived in this paper. Examples are given and discussed to illustrate the general theory. Finally, this consideration is related to the study of refinement masks of spline function vectors.
Computer Aided Geometric Design, 2009
We present a novel approach to the problem of multi-degree reduction of Bézier curves with constraints, using the dual constrained Bernstein basis polynomials, associated with the Jacobi scalar product. We give properties of these polynomials, including the explicit orthogonal representations, and the degree elevation formula. We show that the coefficients of the latter formula can be expressed in terms of dual discrete Bernstein polynomials. This result plays a crucial role in the presented algorithm for multi-degree reduction of Bézier curves with constraints. If the input and output curves are of degree n and m, respectively, the complexity of the method is O (nm), which seems to be significantly less than complexity of most known algorithms. Examples are given, showing the effectiveness of the algorithm.
2010
We propose a novel approach to the problem of multi-degree reduction of Bézier triangular patches with prescribed boundary control points. We observe that the solution can be given in terms of bivariate dual discrete Bernstein polynomials. The algorithm is very efficient thanks to using the recursive properties of these polynomials. The complexity of the method is O(n 2 m 2), n and m being the degrees of the input and output Bézier surfaces, respectively. If the approximation-with appropriate boundary constraints-is performed for each patch of several smoothly joined triangular Bézier surfaces, the result is a composite surface of global C r continuity with a prescribed order r. Some illustrative examples are given.
Journal of Approximation Theory
We introduce a new variant of the blossom, the q-blossom, by altering the diagonal property of the standard blossom. This q-blossom is specifically adapted to developing identities and algorithms for q-Bernstein bases and q-Bézier curves over arbitrary intervals. By applying the q-blossom, we generate several new identities including an explicit formula representing the monomials in terms of the q-Bernstein basis functions and a q-variant of Marsden's identity. We also derive for each q-Bézier curve of degree n, a collection of n! new, affine invariant, recursive evaluation algorithms. Using two of these new recursive evaluation algorithms, we construct a recursive subdivision algorithm for q-Bézier curves.
Loading Preview
Sorry, preview is currently unavailable. You can download the paper by clicking the button above.