Registration for DSA Image Using Triangle Grid and Spatial Transformation Based on Stretching

2006 ◽  
Author(s):  
Ying Chu ◽  
Nan Bai ◽  
Zhen Ji ◽  
Siping Chen ◽  
Xuanqin Mou
Keyword(s):  
Spatial Transformation ◽  
Triangle Grid

Participation and spatial transformation in large housing estates in Poland. Case study of Ursynów Północny

2018 ◽  
Vol 60 (1) ◽  
pp. 55-65
Author(s):  
Krystyna Ilmurzyńska
Keyword(s):  
Basic Assumption ◽  
Real Life ◽  
Business Environment ◽  
Spatial Transformation ◽  
Reciprocal Relationships ◽  
Spatial Transformations ◽  
Large Housing Estates ◽  
Existing Housing ◽  
Housing Estates

Abstract This article investigates the suitability of traditional and participatory planning approaches in managing the process of spatial development of existing housing estates, based on the case study of Warsaw’s Ursynów Północny district. The basic assumption of the article is that due to lack of government schemes targeted at the restructuring of large housing estates, it is the business environment that drives spatial transformations and through that shapes the development of participation. Consequently the article focuses on the reciprocal relationships between spatial transformations and participatory practices. Analysis of Ursynów Północny against the background of other estates indicates that it presents more endangered qualities than issues to be tackled. Therefore the article focuses on the potential of the housing estate and good practices which can be tracked throughout its lifetime. The paper focuses furthermore on real-life processes, addressing the issue of privatisation, development pressure, formal planning procedures and participatory budgeting. In the conclusion it attempts to interpret the existing spatial structure of the estate as a potential framework for a participatory approach.

scholarly journals A Closed-Form Solution to Planar Feature-Based Registration of LiDAR Point Clouds

2021 ◽  
Vol 10 (7) ◽  
pp. 435
Author(s):  
Yongbo Wang ◽  
Nanshan Zheng ◽  
Zhengfu Bian
Keyword(s):  
Closed Form ◽  
Closed Form Solution ◽  
Simulated Data ◽  
Real Data ◽  
Point Clouds ◽  
Form Solution ◽  
Spatial Transformation ◽  
Dual Quaternions ◽  
Feature Based ◽  
Planar Feature

Since pairwise registration is a necessary step for the seamless fusion of point clouds from neighboring stations, a closed-form solution to planar feature-based registration of LiDAR (Light Detection and Ranging) point clouds is proposed in this paper. Based on the Plücker coordinate-based representation of linear features in three-dimensional space, a quad tuple-based representation of planar features is introduced, which makes it possible to directly determine the difference between any two planar features. Dual quaternions are employed to represent spatial transformation and operations between dual quaternions and the quad tuple-based representation of planar features are given, with which an error norm is constructed. Based on L2-norm-minimization, detailed derivations of the proposed solution are explained step by step. Two experiments were designed in which simulated data and real data were both used to verify the correctness and the feasibility of the proposed solution. With the simulated data, the calculated registration results were consistent with the pre-established parameters, which verifies the correctness of the presented solution. With the real data, the calculated registration results were consistent with the results calculated by iterative methods. Conclusions can be drawn from the two experiments: (1) The proposed solution does not require any initial estimates of the unknown parameters in advance, which assures the stability and robustness of the solution; (2) Using dual quaternions to represent spatial transformation greatly reduces the additional constraints in the estimation process.

scholarly journals Effects of Institutions on Spatial Patterns of Manufacturing Industries and Policy Implications in Metropolitan Areas: A Case Study of Wuhan, China

Land ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 710
Author(s):  
Min Zhou ◽  
Man Yuan ◽  
Yaping Huang ◽  
Kaixuan Lin
Keyword(s):  
Spatial Patterns ◽  
Policy Development ◽  
Manufacturing Industries ◽  
Policy Implications ◽  
Land Policy ◽  
Spatial Transformation ◽  
Development Zone ◽  
Analysis Technique ◽  
Spatial System ◽  
Big Cities

Manufacturing space is a spatial system that combines the interaction between capital and institutions at the enterprise, industry, and spatial levels. It is also an important functional type that promotes the spatial evolution of big cities. Most studies focus on the effects of a single institutional type on the manufacturing space of big cities and lack systematic and complete exploration of the institutional mechanism. Current empirical research on typical industrial cities in China is insufficient. This study uses a GIS spatial analysis technique and a Poisson regression model to analyze the mechanism by which institutions have influenced the spatial patterns of manufacturing industries in the Wuhan metropolitan area since the 1990s. The results show that land policy, development zone policy, urban planning, transportation strategy, and eco-environmental policy all have a significant impact on the restructuring process and distribution pattern of the manufacturing industries through incentives and constraints. This study expands our understanding of the influence mechanism of manufacturing spatial patterns and proposes spatial guiding strategies and policy implications for the spatial transformation of urban manufacturing.

scholarly journals Generation of Multiple Vector Optical Bottle Beams

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 218
Author(s):  
Svetlana N. Khonina ◽  
Alexey P. Porfirev ◽  
Sergey G. Volotovskiy ◽  
Andrey V. Ustinov ◽  
Sergey A. Fomchenkov ◽  
...  
Keyword(s):  
Intensity Distribution ◽  
Polarization State ◽  
Spatial Dynamics ◽  
Surface Structures ◽  
Optical Traps ◽  
Spatial Transformation ◽  
Optical Elements ◽  
Periodic Surface ◽  
Matter Interaction ◽  
Different Types

We propose binary diffractive optical elements, combining several axicons of different types (axis-symmetrical and spiral), for the generation of a 3D intensity distribution in the form of multiple vector optical ‘bottle’ beams, which can be tailored by a change in the polarization state of the illumination radiation. The spatial dynamics of the obtained intensity distribution with different polarization states (circular and cylindrical of various orders) were investigated in paraxial mode numerically and experimentally. The designed binary axicons were manufactured using the e-beam lithography technique. The proposed combinations of optical elements can be used for the generation of vector optical traps in the field of laser trapping and manipulation, as well as for performing the spatial transformation of the polarization state of laser radiation, which is crucial in the field of laser-matter interaction for the generation of special morphologies of laser-induced periodic surface structures.

scholarly journals Automatic PET-CT Image Registration Method Based on Mutual Information and Genetic Algorithms

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Martina Marinelli ◽  
Vincenzo Positano ◽  
Francesco Tucci ◽  
Danilo Neglia ◽  
Luigi Landini
Keyword(s):  
Mutual Information ◽  
Optimization Method ◽  
Global Maximum ◽  
Similarity Function ◽  
Spatial Transformation ◽  
Registration Method ◽  
Registration Algorithm ◽  
Positron Emission ◽  
Pet Ct ◽  
Artery Disease

Hybrid PET/CT scanners can simultaneously visualize coronary artery disease as revealed by computed tomography (CT) and myocardial perfusion as measured by positron emission tomography (PET). Manual registration is usually required in clinical practice to compensate spatial mismatch between datasets. In this paper, we present a registration algorithm that is able to automatically align PET/CT cardiac images. The algorithm bases on mutual information (MI) as registration metric and on genetic algorithm as optimization method. A multiresolution approach was used to optimize the processing time. The algorithm was tested on computerized models of volumetric PET/CT cardiac data and on real PET/CT datasets. The proposed automatic registration algorithm smoothes the pattern of the MI and allows it to reach the global maximum of the similarity function. The implemented method also allows the definition of the correct spatial transformation that matches both synthetic and real PET and CT volumetric datasets.

scholarly journals Transformations in the Photogrammetric Co-Processing of Thermal Infrared Images and RGB Images

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5061
Author(s):  
Adam Dlesk ◽  
Karel Vach ◽  
Karel Pavelka
Keyword(s):  
Structure From Motion ◽  
Thermal Infrared ◽  
Processing Method ◽  
Spatial Transformation ◽  
Infrared Images ◽  
Low Resolution ◽  
Thermal Infrared Images ◽  
Rgb Images ◽  
Motion Method

The photogrammetric processing of thermal infrared (TIR) images deals with several difficulties. TIR images ordinarily have low-resolution and the contrast of the images is very low. These factors strongly complicate the photogrammetric processing, especially when a modern structure from motion method is used. These factors can be avoided by a certain co-processing method of TIR and RGB images. Two of the solutions of co-processing were suggested by the authors and are presented in this article. Each solution requires a different type of transformation–plane transformation and spatial transformation. Both types of transformations are discussed in this paper. On the experiments that were performed, there are presented requirements, advantages, disadvantages, and results of the transformations. Both methods are evaluated mainly in terms of accuracy. The transformations are presented on suggested methods, but they can be easily applied to different kinds of methods of co-processing of TIR and RGB images.

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