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We propose a simple method for uniform sampling of points on the surface of a hypersphere in arbitrarily many dimensions. By avoiding the evaluation of computationally expensive functions like logarithms, sines, cosines, or higher order…

Numerical Analysis · Mathematics 2022-05-02 Stefan Schnabel , Wolfhard Janke

We present an efficient method for computing lightcurves of an elliptical source which is microlensed by a point mass. The amplification of an extended source involves a two-dimensional integral over its surface brightness distribution. We…

Astrophysics · Physics 2009-10-30 David Heyrovsky , Abraham Loeb

This work presents a novel framework for spherical mesh parameterization. An efficient angle-preserving spherical parameterization algorithm is introduced, which is based on dynamic Yamabe flow and the conformal welding method with solid…

Graphics · Computer Science 2018-10-23 Saad Nadeem , Zhengyu Su , Wei Zeng , Arie Kaufman , Xianfeng Gu

A new method is proposed to divide a spherical surface into equal-area cells. The method is based on dividing a sphere into several latitudinal bands of near-constant span with further division of each band into equal-area cells. It is…

Instrumentation and Methods for Astrophysics · Physics 2019-05-08 Zinovy Malkin

We construct measure-preserving mappings from the $d$-dimensional unit cube to the $d$-dimensional unit ball and the compact rank one symmetric spaces, namely the $d$-dimensional sphere, the real, complex, and quaternionic projective…

Classical Analysis and ODEs · Mathematics 2025-02-25 Carlos Beltrán , Damir Ferizović , Pedro R. López-Gómez

We propose a new effective method called spherical authalic energy minimization (SAEM) for computing spherical area-preserving parameterizations of genus-zero surfaces. The proposed SAEM has solid theoretical support and guaranteed…

Numerical Analysis · Mathematics 2024-12-30 Shu-Yung Liu , Mei-Heng Yueh

An area-preserving parameterization is a bijective mapping that maps a surface onto a specified domain and preserves the local area. This paper formulates the computation of disk area-preserving parameterization as an authalic energy…

Numerical Analysis · Mathematics 2023-11-08 Shu-Yung Liu , Mei-Heng Yueh

We present and discuss several old and new methods for mapping a circular disc to a square. In particular, we present analytical expressions for mapping each point (u,v) inside the circular disc to a point (x,y) inside a square region.…

History and Overview · Mathematics 2024-12-30 Chamberlain Fong

Environment maps with high dynamic range lighting, such as daylight sky maps, require importance sampling to keep the balance between noise and number of samples per pixel manageable. Typically, importance sampling schemes for environment…

Graphics · Computer Science 2022-08-24 Martin Lambers

Let $f=h+\overline{g}$ be a harmonic univalent map in the unit disk $\mathbb{D}$, where $h $ and $g$ are analytic. We obtain an improved estimate for the second coefficient of $h$. This indeed is the first qualitative improvement after the…

Complex Variables · Mathematics 2018-07-17 Yusuf Abu Muhanna , Rosihan M. Ali , Saminathan Ponnusamy

We develop a sampling scheme on the sphere that permits accurate computation of the spherical harmonic transform and its inverse for signals band-limited at $L$ using only $L^2$ samples. We obtain the optimal number of samples given by the…

Information Theory · Computer Science 2014-07-25 Zubair Khalid , Rodney A. Kennedy , Jason D. McEwen

We present and discuss different algorithms for converting rectangular imagery into elliptical regions. We mainly focus on methods that use mathematical mappings with explicit and invertible equations. The key idea is to start with…

Image and Video Processing · Electrical Eng. & Systems 2019-11-13 Chamberlain Fong

We construct sense-preserving univalent harmonic mappings which map the unit disk onto a domain which is convex in the horizontal direction, but with varying dilatation. Also, we obtain minimal surfaces associated with such harmonic…

Complex Variables · Mathematics 2015-08-04 YuePing Jiang , ZhiHong Liu , Saminathan Ponnusamy

The parameterization of open and closed anatomical surfaces is of fundamental importance in many biomedical applications. Spherical harmonics, a set of basis functions defined on the unit sphere, are widely used for anatomical shape…

Computational Geometry · Computer Science 2022-06-30 Gary P. T. Choi , Amita Giri , Lalan Kumar

We propose a sampling scheme that can perfectly reconstruct a collection of spikes on the sphere from samples of their lowpass-filtered observations. Central to our algorithm is a generalization of the annihilating filter method, a tool…

Information Theory · Computer Science 2016-01-20 Ivan Dokmanic , Yue M. Lu

For a class of polyhedrons denoted $\mathbb K_n(r,\varepsilon)$, we construct a bijective continuous area preserving map from $\mathbb K_n(r,\varepsilon)$ to the sphere $\mathbb S^{2}(r)$, together with its inverse. Then we investigate for…

Metric Geometry · Mathematics 2015-04-08 Adrian Holhoş , Daniela Roşca

Predicting the pose of objects from a single image is an important but difficult computer vision problem. Methods that predict a single point estimate do not predict the pose of objects with symmetries well and cannot represent uncertainty.…

Computer Vision and Pattern Recognition · Computer Science 2023-02-28 David M. Klee , Ondrej Biza , Robert Platt , Robin Walters

Stratified sampling is a fast and simple method to generate point sets with uniform distribution in hypercubes. However, for the most common paraxial stratfication it has the prominent drawback that the number of sampled points in n…

Computation · Statistics 2018-06-14 Simon Wessing

We introduce a new sphericalization mapping for metric spaces that is applicable in very general situations, including totally disconnected fractal type sets. For an unbounded complete metric space which is uniformly perfect at a base point…

Functional Analysis · Mathematics 2026-05-01 Anders Björn , Jana Björn , Riikka Korte , Sari Rogovin , Timo Takala

The growing use of wide angle image capture devices and the need for fast and accurate image analysis in computer visions have enforced the need for dedicated under-representation approaches. Most recent decomposition methods segment an…

Computer Vision and Pattern Recognition · Computer Science 2025-09-25 Rémi Giraud , Rodrigo Borba Pinheiro , Yannick Berthoumieu
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