Kirchhoff inversion in image point coordinates recast as source/receiver point processing

2005 ◽  
Author(s):  
N. Bleistein ◽  
Y. Zhang ◽  
S. Xu ◽  
G. Zhang ◽  
S. H. Gray
Keyword(s):  
Image Point ◽  
Receiver Point

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

New polarized-light microscope for fast and orientation independent measurement of birefringent fine structure

1993 ◽  
Vol 51 ◽  
pp. 82-83
Author(s):  
Rudolf Oldenbourg
Keyword(s):  
Light Microscope ◽  
Polarized Light ◽  
Video Camera ◽  
Limited Range ◽  
Image Point ◽  
Computer Assisted ◽  
Optical Modulators ◽  
Anisotropic Structures ◽  
Long Time ◽  
Computer Assisted Image

The polarized light microscope has the unique potential to measure submicroscopic molecular arrangements dynamically and non-destructively in living cells and other specimens. With the traditional pol-scope, however, single images display only those anisotropic structures that have a limited range of orientations with respect to the polarization axes of the microscope. Furthermore, rapid measurements are restricted to a single image point or single area that exhibits uniform birefringence or other form of optical anisotropy, while measurements comparing several image points take an inordinately long time.We are developing a new kind of polarized light microscope which combines speed and high resolution in its measurement of the specimen anisotropy, irrespective of its orientation. The design of the new pol-scope is based on the traditional polarized light microscope with two essential modifications: circular polarizers replace linear polarizers and two electro-optical modulators replace the traditional compensator. A video camera and computer assisted image analysis provide measurements of specimen anisotropy in rapid succession for all points of the image comprising the field of view.

Monocular Structure from Motion Based on Angular BA

2015 ◽  
Vol 742 ◽  
pp. 290-293
Author(s):  
Xiu Zhi Li ◽  
Ai Lin Yang ◽  
Huan Qiu ◽  
Song Min Jia
Keyword(s):  
Optical Flow ◽  
Structure From Motion ◽  
Structure Refinement ◽  
3D Structure ◽  
Flow Fields ◽  
Image Point ◽  
Pixel Pair ◽  
Pair Matching ◽  
Dense Correspondence

This paper presents a technique for monocular Structure from Motion (SFM) that reconstructs 3D world shape. The technique proposed uses optical flow for 2D pixel pair matching and Angular Bundle Ajustment (ABA) for 3D structure refinement. The proposed strategy has two main advantages. Firstly, optical flow fields provide sufficient dense correspondence of image point pairs and secondly, ABA outperforms classic BA variants, especially for the points relatively far from camera. The reconstruction results obtained in realistic scenario demonstrate the effectiveness and accuracy of the proposed algorithm.

Dimension-Descending Algorithm for Spherical Delaunay Triangulation

2011 ◽  
Vol 130-134 ◽  
pp. 2915-2919
Author(s):  
Ping Duan ◽  
Jia Tian Li ◽  
Jia Li
Keyword(s):  
Delaunay Triangulation ◽  
Time Complexity ◽  
Image Point ◽  
Spherical Space ◽  
Projected Image ◽  
Plane Image ◽  
Projection Center ◽  
Space Data ◽  
Construction Algorithms ◽  
Main Construction

Spherical Delaunay triangulation (SDT) which is a powerful tool to represent, organize and analyze spherical space data has become a focus of spherical GIS research. Projection stitching algorithm is one of the main construction algorithms of SDT. The basic idea of stitching algorithm is that the sphere is divided into two hemispheres to avoid projected image point coincidence. So, the practicality of projection stitching algorithm is lower because of merging two hemispheres. Aimed at the disadvantage of projection stitching algorithm, this paper puts forward a new algorithm to construct SDT used perspective projection principle. The projection center is placed on sphere to establish one-to-one mapping between spherical space points and plane image points. Experiment shows that the time complexity of our algorithm depends on Delaunay triangulation construction algorithm of the plane.

scholarly journals The optimum orientation of an absorbing barrier

2005 ◽  
Vol 461 (2060) ◽  
pp. 2369-2383 ◽  
Author(s):  
A.D Rawlins
Keyword(s):  
Noise Level ◽  
Noise Source ◽  
Shadow Region ◽  
Source Position ◽  
Absorbent Material ◽  
Noise Barrier ◽  
Receiver Point

In the following work, we solve the problem of the best orientation of a rigid noise barrier, which has one face lined with absorbent material, between a noise source and a receiver point in the shadow region of the barrier. By the ‘best orientation’, we mean that positioning of the barrier which yields the least noise level at the receiving point for a given barrier and source position.

scholarly journals Transferability of ALS-based forest attribute models when predicting with drone-based image point cloud data

2021 ◽  
Vol 103 ◽  
pp. 102484
Author(s):  
Janne Toivonen ◽  
Lauri Korhonen ◽  
Mikko Kukkonen ◽  
Eetu Kotivuori ◽  
Matti Maltamo ◽  
...  
Keyword(s):  
Point Cloud ◽  
Image Point ◽  
Point Cloud Data ◽  
Cloud Data

scholarly journals Visual Measurement System for Wheel–Rail Lateral Position Evaluation

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1297
Author(s):  
Viktor Skrickij ◽  
Eldar Šabanovič ◽  
Dachuan Shi ◽  
Stefano Ricci ◽  
Luca Rizzetto ◽  
...  
Keyword(s):  
Measurement System ◽  
Inertial Sensor ◽  
Low Cost ◽  
Image Point ◽  
Low Velocity ◽  
Point Selection ◽  
Lateral Direction ◽  
Initial Field ◽  
Visual Measurement ◽  
Track Geometry

Railway infrastructure must meet safety requirements concerning its construction and operation. Track geometry monitoring is one of the most important activities in maintaining the steady technical conditions of rail infrastructure. Commonly, it is performed using complex measurement equipment installed on track-recording coaches. Existing low-cost inertial sensor-based measurement systems provide reliable measurements of track geometry in vertical directions. However, solutions are needed for track geometry parameter measurement in the lateral direction. In this research, the authors developed a visual measurement system for track gauge evaluation. It involves the detection of measurement points and the visual measurement of the distance between them. The accuracy of the visual measurement system was evaluated in the laboratory and showed promising results. The initial field test was performed in the Vilnius railway station yard, driving at low velocity on the straight track section. The results show that the image point selection method developed for selecting the wheel and rail points to measure distance is stable enough for TG measurement. Recommendations for the further improvement of the developed system are presented.

scholarly journals Infrared and visual image point set registration based on sensor parameters and refined CPD algorithm

2012 ◽  
Vol 31 (2) ◽  
pp. 171-176 ◽  
Author(s):  
Peng WANG ◽  
Ying-Hui GAO ◽  
Ping WANG ◽  
Zhi-Guo QU ◽  
Zhen-Kang SHEN
Keyword(s):  
Visual Image ◽  
Image Point ◽  
Point Set Registration ◽  
Point Set

scholarly journals FAST REGISTRATION OF TERRESTRIAL LIDAR POINT CLOUD AND SEQUENCE IMAGES

2017 ◽  
Vol XLII-2/W7 ◽  
pp. 875-879
Author(s):  
J. Shao ◽  
W. Zhang ◽  
Y. Zhu ◽  
A. Shen
Keyword(s):  
Point Cloud ◽  
Engineering Application ◽  
Image Point ◽  
Color Information ◽  
Registration Accuracy ◽  
Registration Method ◽  
Terrestrial Lidar ◽  
The Rich ◽  
Ground Based Lidar

Image has rich color information, and it can help to promote recognition and classification of point cloud. The registration is an important step in the application of image and point cloud. In order to give the rich texture and color information for LiDAR point cloud, the paper researched a fast registration method of point cloud and sequence images based on the ground-based LiDAR system. First, calculating transformation matrix of one of sequence images based on 2D image and LiDAR point cloud; second, using the relationships of position and attitude information among multi-angle sequence images to calculate all transformation matrixes in the horizontal direction; last, completing the registration of point cloud and sequence images based on the collinear condition of image point, projective center and LiDAR point. The experimental results show that the method is simple and fast, and the stitching error between adjacent images is litter; meanwhile, the overall registration accuracy is high, and the method can be used in engineering application.

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