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Centroid

About: Centroid is a research topic. Over the lifetime, 4110 publications have been published within this topic receiving 53637 citations. The topic is also known as: barycenter (geometry) & geometric center of a plane figure.


Papers
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Journal ArticleDOI
TL;DR: A novel shape descriptor, triangular centroid distances (TCDs) is proposed, for shape representation; the TCDs shape descriptor is invariant to translation, rotation, scaling, and considerable shape deformations and outperforms existing methods in 2D nonrigid partial shape matching.

39 citations

Journal ArticleDOI
TL;DR: In this article, the accuracy of centroid algorithms in 1D, 2D and 3D can be investigated and three factors that can influence the method's accuracy have been investigated: systematic error of the algorithm, influence of photon noise and the influence of perturbations such as scanning nonlinearity.
Abstract: The accuracy with which centroid algorithms in 1D, 2D and 3D can estimate an object's position has been investigated. Three factors that can influence the method's accuracy have been investigated: systematic error of the algorithm, influence of photon noise and the influence of perturbations such as scanning nonlinearity. The variation of the accuracy with parameters that are relevant for confocal microscopy, such as object diameter and photon noise/pixel, has been considered. Theory and simulations presented show that the variation of the accuracy with respect to such parameters can differ drastically between the 1D, 2D and 3D cases. Experiments performed using microspheres show that the magnitudes of the three types of error can be approximately the same under normal operating conditions and that it is therefore necessary to take all three into account when assessing the total error.

39 citations

Journal ArticleDOI
TL;DR: Novel algorithms and the underlying mathematics to process photographs of planetary illuminated bodies and use them for navigation purposes to provide autonomous navigation capabilities to spacecrafts by observing a planet or a moon are introduced.
Abstract: This study introduces novel algorithms and the underlying mathematics to process photographs of planetary illuminated bodies and use them for navigation purposes. The goal is to accurately estimate the observer-to-body relative position in inertial coordinates. The main motivation is to provide autonomous navigation capabilities to spacecrafts by observing a planet or a moon. This is needed, for example, in human-rated vehicles in order to provide navigation capabilities in a loss-of-communications scenario. The algorithm is derived for the general case of a triaxial ellipsoid that is observed bounded by an elliptical cone. The orientation of the elliptical cone reference frame is obtained by eigenanalysis, and the offset between the elliptical cone axis and the body center direction as well as the equation of the terminator are quantified. The main contribution of this paper is in the image-processing approach adopted to derive centroid and distance to the body. This is done by selecting a set of pixels ...

39 citations

Journal ArticleDOI
TL;DR: In this paper, two functions describing a closed curve are proposed and applied to synthesis of 1-DOF planar geared five-bar mechanism as a path generator, which are represented by normalized coefficients of their expansions into Fourier series.

39 citations

Journal ArticleDOI
20 Mar 2019
TL;DR: In this article, the centroid estimation of spatially quantum-correlated biphotons is used to enhance the spatial resolution of a general non-fluorescing object using low energy and low-intensity infrared illumination.
Abstract: The spatial resolution of an optical system is limited by diffraction. Various schemes have been proposed to achieve resolution enhancement by employing either a scanning source/detector configuration or a two-photon response of the object. Here, we experimentally demonstrate a full-field resolution-enhancing scheme, based on the centroid estimation of spatially quantum-correlated biphotons. Our standard-quantum-limited scheme is able to image a general non-fluorescing object, using low-energy and low-intensity infrared illumination (i.e., with <0.001 photon per pixel per frame at 710 nm), achieving 41% of the theoretically available resolution enhancement. Images of real-world objects are shown for visual comparison, in which the classically bound resolution is surpassed using our technically straightforward quantum-imaging scheme.

39 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023492
20221,001
2021184
2020202
2019269
2018271