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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 fast point-based image registration method for the suppression of the movement of a cell as a whole in the image data is proposed and the results show that the method is very well suited to live cell imaging.
Abstract: Typical time intervals between acquisitions of three-dimensional (3-D) images of the same cell in live cell imaging are in the orders of minutes. In the meantime, the live cell can move in a water basin on the stage. This movement can hamper the studies of intranuclear processes. We propose a fast point-based image registration method for the suppression of the movement of a cell as a whole in the image data. First, centroids of certain intracellular objects are computed for each image in a time-lapse series. Then, a matching between the centroids, which have the maximal number of pairs, is sought between consecutive point sets by a 3-D extension of a two-dimensional fast point pattern matching method, which is invariant to rotation, translation, local distortion, and extra/missing points. The proposed 3-D extension assumes rotations only around the z axis to retain the complexity of the original method. The final step involves computing the optimal fully 3-D transformation between images from corresponding points in the least-squares manner. The robustness of the method was evaluated on generated data. The results of the simulations show that the method is very precise and its correctness can be estimated. This article also presents two practical application examples, namely the registration of images of HP1 domains and the registration of images of telomeres. More than 97% of time-consecutive images were successfully registered. The results show that the method is very well suited to live cell imaging.

38 citations

Journal ArticleDOI
TL;DR: The usefulness of the method for practical applications is demonstrated by considering a sequence of real target images of about 20 pixels in size in a noisy urban environment where the measurement noise was calculated as having 0.32 pixel RMS value.
Abstract: In the authors' previous work Oron, Kumar, and Bar-Shalom (1993), they presented a method for precision tracking of a low observable target based on data obtained from imaging sensors. The image was divided into several layers of gray level intensities and thresholded. A binary image was obtained and grouped into clusters using image segmentation techniques. Using the centroid measurements of the clusters, the probabilistic data association filter (PDAF) was employed for tracking the target centroid. In this correspondence, the division of the image into several layers of gray level intensities is optimized by minimizing the Bayes risk. This optimal layering of the image has the following properties: (1) following the segmentation, a closed-form analytical expression is obtained for the noise variance of the centroid measurement based on a single frame; (2) in comparison to the previous paper, the measurement noise variance is smaller by at least a factor of 2, thus improving the performance of the tracker. The usefulness of the method for practical applications is demonstrated by considering a sequence of real target images (a moving car) of about 20 pixels in size in a noisy urban environment where the measurement noise was calculated as having 0.32 pixel RMS value. Filtering with the PDAF further reduces this by a factor of 1.6. >

38 citations

Patent
08 Nov 1994
TL;DR: In this article, the authors proposed a method to automatically set a region of interest (ROI) suitable for the area of an atrium, etc., in an ultrasonic diagnostic system.
Abstract: PURPOSE: To automatically set a region of interest(ROI) suitable for the area of an atrium, etc., in an ultrasonic diagnostic system. CONSTITUTION: The contour point detecting part 42 of an automatic ROI setting part 40 detects the contour point of a bloodstream area along each ultrasonic beam of sector scan. A centroid coordinate arithmetic part 44 finds the centroid of contour point groups from the coordinates of detected contour points. A moment of inertia arithmetic part 46 performs the coordinate transformation of the coordinate of each contour point to a centroid coordinate system setting the centroid as an origin, and finds the moment of inertia and products of inertia of the contour point group around each coordinate axis. An inertia main spindle arithmetic part 48 finds the inclination of an inertia main spindle for the centroid coordinate system based on the moment of inertia and the products of inertia. A ROI arithmetic part 50 finds the inertia main spindle based on the inclination, and decides the length of the major axis and minor axis of an elliptical ROI from the coordinate of the contour point in the neighborhood of the inertia main spindle, and sets the ROI so as to align the major axis and the minor axis with each inertia main spindle.

38 citations

Journal ArticleDOI
TL;DR: A straightforward algorithm for sizing and locating multiple DG units in radial/meshed distribution network is developed and results confirm stability, integrity and efficacy of the proposed approach.
Abstract: Allocation of distributed generation (DG) units is commonly formulated as a constrained nonlinear optimization problem solved by complex iterative mathematical or heuristic techniques. Heavy computational burden, very long solution time, probable divergence and possibility of getting only a sub-optimal solution are some serious drawbacks. In this paper, a systematic simple approach to allocate multiple DG units in radial/meshed distribution network is proposed. The concept of equivalent load is introduced and extended to identify the load centroid precisely with two methods. A performance index that combines the power system real power loss and average node voltage is defined. Based on load centroid and performance index, a straightforward algorithm for sizing and locating multiple DG units is developed. The proposed technique is applied to radial and meshed test systems. Results confirm stability, integrity and efficacy of the proposed approach.

38 citations

Journal ArticleDOI
TL;DR: A novel and efficient method for dorsal hand vein recognition by improving two major steps of the SIFT-like framework, i.e. key-point detection and matching and fine-grained matching is introduced which makes use of Multi-task Sparse Representation Classifier.

38 citations


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