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Delineating the lesion area is an important task in image-based diagnosis. Pixel-wise classification is a popular approach to segmenting the region of interest. However, at fuzzy boundaries such methods usually result in glitches,…

Computer Vision and Pattern Recognition · Computer Science 2021-08-03 Haichou Chen , Yishu Deng , Bin Li , Zeqin Li , Haohua Chen , Bingzhong Jing , Chaofeng Li

We provide improved error bounds for kernel-based numerical differentiation in terms of growth functions when kernels are of a finite smoothness, such as polyharmonic splines, thin plate splines or Wendland kernels. In contrast to existing…

Numerical Analysis · Mathematics 2025-12-24 Oleg Davydov

Cut and project sets are obtained by taking an irrational slice of a lattice and projecting it to a lower dimensional subspace, and are fully characterised by the shape of the slice (window) and the choice of the lattice. In this context we…

Number Theory · Mathematics 2024-08-27 Henna Koivusalo , Jean Lagacé , Michael Björklund , Tobias Hartnick

Spectral clustering is discussed from many perspectives, by extending it to rectangular arrays and discrepancy minimization too. Near optimal clusters are obtained with singular value decomposition and with the weighted $k$-means algorithm.…

Combinatorics · Mathematics 2022-01-06 Marianna Bolla , Vilas Winstein , Tao You , Frank Seidl , Fatma Abdelkhalek

An algorithm is proposed for the segmentation of image into multiple levels using mean and standard deviation in the wavelet domain. The procedure provides for variable size segmentation with bigger block size around the mean, and having…

We consider the two-point correlation function of the photodissociation cross section in molecules where the fragmentation process is indirect, passing through resonances above the dissociation threshold. In the limit of overlapping…

Condensed Matter · Physics 2009-10-31 Oded Agam

In this article, we consider `$N$'spherical caps of area $4\pi p$ were uniformly distributed over the surface of a unit sphere. We are giving the strong threshold function for the size of random caps to cover the surface of a unit sphere.…

Probability · Mathematics 2008-09-09 Bhupendra Gupta

K. Bezdek and Gy. Kiss showed that existence of origin-symmetric coverings of unit sphere in $\mathbb{E}^n$ by at most $2^n$ congruent spherical caps with radius not exceeding $\arccos\sqrt{\frac{n-1}{2n}}$ implies the $X$-ray conjecture…

Metric Geometry · Mathematics 2025-04-15 A. Bondarenko , A. Prymak , D. Radchenko

We study lattice points in d-dimensional spheres, and count their number in thin spherical segments. We found an upper bound depending only on the radius of the sphere and opening angle of the segment. To obtain this bound we slice the…

Number Theory · Mathematics 2020-07-14 Martin Ortiz Ramirez

The classical Stolarsky invariance principle connects the spherical cap $L^2$ discrepancy of a finite point set on the sphere to the pairwise sum of Euclidean distances between the points. In this paper we further explore and extend this…

Classical Analysis and ODEs · Mathematics 2016-11-15 Dmitriy Bilyk , Feng Dai , Ryan Matzke

In this paper, we study a partially overdetermined mixed boundary value problem in a half ball. We prove that a domain in which this partially overdetermined problem admits a solution if and only if the domain is a spherical cap…

Analysis of PDEs · Mathematics 2019-08-08 Jinyu Guo , Chao Xia

Scientific exploitation of the ever increasing volumes of astronomical data requires efficient and practical methods for data access, visualisation, and analysis. Hierarchical sky tessellation techniques enable a multi-resolution approach…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 P. Fernique , M. G. Allen , T. Boch , A. Oberto , F-X. Pineau , D. Durand , C. Bot , L. Cambresy , S. Derriere , F. Genova , F. Bonnarel

In industrial defect segmentation tasks, while pixel accuracy and Intersection over Union (IoU) are commonly employed metrics to assess segmentation performance, the output consistency (also referred to equivalence) of the model is often…

Computer Vision and Pattern Recognition · Computer Science 2023-10-02 Zhen Qu , Xian Tao , Fei Shen , Zhengtao Zhang , Tao Li

Based on a quantitative version of the inverse function theorem and an appropriate saddle-point formulation we derive a quasi-optimal error estimate for the finite element approximation of harmonic maps into spheres with a nodal…

Numerical Analysis · Mathematics 2022-09-27 Sören Bartels , Christian Palus , Zhangxian Wang

We study a class of exceptional minimal surfaces in spheres for which all Hopf differentials are holomorphic. Extending results of Eschenburg and Tribuzy \cite{ET0}, we obtain a description of exceptional surfaces in terms of a set of…

Differential Geometry · Mathematics 2015-06-30 Theodoros Vlachos

We study the behaviour of the minimal solution to the Gelfand problem on a spherical cap under the Dirichlet boundary conditions. The asymptotic behaviour of the solution is discussed as the cap approaches the whole sphere. The results are…

Analysis of PDEs · Mathematics 2021-08-06 Yoshitsugu Kabeya , Vitaly Moroz

The surface area of a set which is only observed as a binary pixel image is often estimated by a weighted sum of pixel configurations counts. In this paper we examine these estimators in a design based setting -- we assume that the observed…

Statistics Theory · Mathematics 2019-06-20 Jürgen Kampf

Various packing problems and simulations of hard and soft interacting particles, such as microscopic models of nematic liquid crystals, reduce to calculations of intersections and pair interactions between ellipsoids. When constrained to a…

Soft Condensed Matter · Physics 2022-10-12 Andraž Gnidovec , Anže Božič , Urška Jelerčič , Simon Čopar

The core of our approach, Pixel Consensus Voting, is a framework for instance segmentation based on the Generalized Hough transform. Pixels cast discretized, probabilistic votes for the likely regions that contain instance centroids. At the…

Computer Vision and Pattern Recognition · Computer Science 2020-04-07 Haochen Wang , Ruotian Luo , Michael Maire , Greg Shakhnarovich

In this paper a hierarchical model for pixel clustering and image segmentation is developed. In the model an image is hierarchically structured. The original image is treated as a set of nested images, which are capable to reversibly merge…

Computer Vision and Pattern Recognition · Computer Science 2016-12-22 Mikhail Kharinov