scholarly journals ASSESSMENT OF FEATURE DETECTORS AND DESCRIPTORS IN REMOTE IMAGES OF PLANETARY BODIES

2019 ◽  
Vol XLII-2/W13 ◽  
pp. 1451-1456
Author(s):  
E. J. Speyerer
Keyword(s):  
Feature Matching ◽  
Natural Landscape ◽  
New Approach ◽  
Control Networks ◽  
Common Features ◽  
Ideal Detector ◽  
Mapping Tool ◽  
Feature Detectors ◽  
Planetary Bodies ◽  
Image Set

<p><strong>Abstract.</strong> Algorithms to detect, describe, and match common features in image sets are expanding to new worlds with the integration of the OpenCV feature matching framework in a popular mapping tool for planetary images (ISIS3). These algorithms provide a new approach to register images and build image-based control networks. However, the natural landscape of the Moon and other planetary bodies pose new challenges such as numerous features that appear similar (i.e., impact craters and boulders). In addition, planetary image sets vary in scale, orientation, and noise properties, especially when conducting cross instrument and cross mission comparisons. This study assesses a collection of common feature detector and descriptor algorithms to examine how they adapt to these challenges. With our analysis, we did not identify an ideal detector and descriptor combination that exists for our diverse lunar dataset. However, we did identify where particular algorithms succeed and identify their shortcomings. By knowing these capabilities, users can identify the proper set of algorithms to apply to an image set given the presence of noise and variations to scale and orientation.</p>

scholarly journals Design of local heterogeneous system control networks of a new generation with the preservation of the optimality of the main topological functionals of the network

2021 ◽  
Vol 2091 (1) ◽  
pp. 012038
Author(s):  
M F Karavay ◽  
A M Mikhailov
Keyword(s):  
Control System ◽  
System Control ◽  
Computer Engineering ◽  
New Approach ◽  
Control Networks ◽  
Parallel Tasks ◽  
Parallel Mode ◽  
New Generation ◽  
Very High Frequencies ◽  
Weapons Control

Abstract The paper discusses On-Board Computing Control Systems (OBCS) in astronautics, avionics, autonomous mobile devices, robotics, weapons control and multi-core microprocessors. This is sort of a “backbone”, which unites many sensors, calculators, control and executive devices. The architecture of these networks was developed some 30-40 years ago. At that time, these systems met the technical conditions in terms of dynamics and reliability. Nowadays, these systems must perform their functions for 10 to 15 years without maintenance. The performance of system networks must be high enough to solve such tasks as monitoring “swarms” that comprise hundreds of objects or work as a “garbage collectors” in space orbits. Nevertheless modern system networks continue to be based on bus or multi-bus architectures. Since these systems are serial for active nodes, a multi-bus solution is a main way to increase the performance of networks by using very high frequencies that amount to 2 ÷ 4 GHz. It’s an extensive path of development, which is problematic. More acceptable would be an intensive path of development, which, in electronics and computer engineering, is associated with the parallelism of task execution. It means that the operating frequencies may not be ultra-high, not exceeding that of modern devices for frequencies of 10 – 600 MHz. However, such devices should work in a parallel mode. The paper proposes a new approach to designing of heterogeneous parallel control system networks, solving parallel tasks, and a conflict-free management of “passive” nodes. To the best of our knowledge, such control system networks are not available as yet.

Explaining feature detection Mechanisms: A Survey

2021 ◽  
pp. 51-64
Author(s):  
Ahmed A. Elngar ◽  
◽  
◽  
◽  
◽  
...  
Keyword(s):  
Feature Detection ◽  
Feature Matching ◽  
Image Features ◽  
Mathematical Concepts ◽  
Detection Algorithms ◽  
Feature Detectors ◽  
Essential Components ◽  
Basic Notation ◽  
Computer Vision Applications ◽  
Detection Mechanisms

Feature detection, description and matching are essential components of various computer vision applications; thus, they have received a considerable attention in the last decades. Several feature detectors and descriptors have been proposed in the literature with a variety of definitions for what kind of points in an image is potentially interesting (i.e., a distinctive attribute). This chapter introduces basic notation and mathematical concepts for detecting and describing image features. Then, it discusses properties of perfect features and gives an overview of various existing detection and description methods. Furthermore, it explains some approaches to feature matching. Finally, the chapter discusses the most used techniques for performance evaluation of detection algorithms.

scholarly journals A PERFORMANCE COMPARISON OF FEATURE DETECTORS FOR PLANETARY ROVER MAPPING AND LOCALIZATION

2017 ◽  
Vol XLII-3/W1 ◽  
pp. 149-154 ◽  
Author(s):  
W. Wan ◽  
M. Peng ◽  
Y. Xing ◽  
Y. Wang ◽  
Z. Liu ◽  
...  
Keyword(s):  
Feature Detection ◽  
Feature Matching ◽  
Comprehensive Evaluation ◽  
Evaluation Criteria ◽  
Performance Comparison ◽  
Stereo Images ◽  
Feature Detectors ◽  
Comparison Results ◽  
Feature Based ◽  
Key Techniques

Feature detection and matching are key techniques in computer vision and robotics, and have been successfully implemented in many fields. So far there is no performance comparison of feature detectors and matching methods for planetary mapping and rover localization using rover stereo images. In this research, we present a comprehensive evaluation and comparison of six feature detectors, including Moravec, Förstner, Harris, FAST, SIFT and SURF, aiming for optimal implementation of feature-based matching in planetary surface environment. To facilitate quantitative analysis, a series of evaluation criteria, including distribution evenness of matched points, coverage of detected points, and feature matching accuracy, are developed in the research. In order to perform exhaustive evaluation, stereo images, simulated under different baseline, pitch angle, and interval of adjacent rover locations, are taken as experimental data source. The comparison results show that SIFT offers the best overall performance, especially it is less sensitive to changes of image taken at adjacent locations.

Platypnea-Orthodeoxia in Patients on Hemodialysis: A New Approach to Its Pathophysiology and Implications for Treatment

Cardiology ◽  
2015 ◽  
Vol 133 (4) ◽  
pp. 213-216 ◽  
Author(s):  
Subeer Wadia ◽  
Stephen Boateng ◽  
Damien Kenny ◽  
Clifford Kavinsky
Keyword(s):  
Clinical Presentation ◽  
Clinical Syndrome ◽  
Balloon Occlusion ◽  
Upright Position ◽  
Specific Patient ◽  
New Approach ◽  
Clinical Pattern ◽  
Common Features ◽  
The Common ◽  
Low Prevalence

Platypnea-orthodeoxia is a poorly understood clinical syndrome resulting in dyspnea and hypoxemia in the upright position, which diminishes with recumbency. Recognition of the disease is limited by its low prevalence and decreased awareness among clinicians. However, understanding the disease, its pathophysiology, its clinical presentation, and the possible therapeutic options is vital in the management of these patients. Here, we present 2 cases of platypnea- orthodeoxia where oxygen saturations worsened with hemodialysis. After highlighting the common features in the clinical pattern of each patient, we present a pressure-mediated pathophysiologic mechanism (in contrast to a previously reported morphologically based hypothesis) to explain the characteristic effects of hemodialysis on hypoxia in platypnea-orthodeoxia. We present a novel diagnostic approach using balloon occlusion testing when the diagnosis is unclear and illustrate how treatments can be tailored to the comorbidities of a specific patient.

ULVS XXVII: Mapping and Spatial Analysis of the Libyan Valleys Data using GIS

1995 ◽  
Vol 26 ◽  
pp. 49-78 ◽  
Author(s):  
C. P. J. Flower ◽  
D. J. Mattingly
Keyword(s):  
Information System ◽  
Spatial Analysis ◽  
Geographical Information System ◽  
Survey Data ◽  
Final Section ◽  
Geographical Information ◽  
New Approach ◽  
Site Distribution ◽  
Mapping Tool ◽  
The Way

AbstractThis article presents a new approach to the analysis of the UNESCO Libyan Valleys Survey data, using a Geographical Information System (GIS) for mapping and spatial analysis of site distribution. The first section of the article describes the way in which the GIS was compiled and linked to the computerised gazetteer database. The second section demonstrates the use of the system as a mapping tool, shedding new light on the settlement trends in the region through time. The final section of the article explores in greater depth some aspects of its potential in sophisticated spatial analysis.

CHARACTERISTICS OF DISCONTINUOUS AND NONINVERTIBLE 2-D MAPS

2007 ◽  
Vol 21 (23n24) ◽  
pp. 3960-3966 ◽  
Author(s):  
DA-REN HE
Keyword(s):  
Phase Space ◽  
Two Dimensional ◽  
Attraction Basin ◽  
Common Features ◽  
Image Set ◽  
The Common ◽  
Different Characteristics ◽  
Area Preserving ◽  
Stochastic Web

This paper presents a review on recent investigations about the classic dynamics general features of the noninvertible and discontinuous two-dimensional maps. For concreteness we consider a system with phase space divided into two distinct but complementary regions R1 and R2. They are the domains of the map functions f1(x) and f2(x), respectively. The common features of the systems include: the stochastic web formed by image set of discontinuous borderline; phase collapse caused by the irreversibility (quasi-dissipation); fat fractal forbidden web; riddled-like attraction basin and the induced unpredictability of attractors. Several different cases where f1(x) and f2(x) are both area preserving; one is area preserving and another is dissipative; or both are dissipative have been studied. In all the cases the dynamics features can be displayed, however with different characteristics. The features are interesting and can be verified experimentally.

scholarly journals Exchangeable Generative Models with Flow Scans

2020 ◽  
Vol 34 (06) ◽  
pp. 10053-10060
Author(s):  
Christopher Bender ◽  
Kevin O'Connor ◽  
Yang Li ◽  
Juan Garcia ◽  
Junier Oliva ◽  
...  
Keyword(s):  
Density Estimation ◽  
Local Structure ◽  
Point Cloud ◽  
State Of The Art ◽  
Generative Models ◽  
New Approach ◽  
Sequential Methods ◽  
Image Set ◽  
Art Performance ◽  
Global And Local

In this work, we develop a new approach to generative density estimation for exchangeable, non-i.i.d. data. The proposed framework, FlowScan, combines invertible flow transformations with a sorted scan to flexibly model the data while preserving exchangeability. Unlike most existing methods, FlowScan exploits the intradependencies within sets to learn both global and local structure. FlowScan represents the first approach that is able to apply sequential methods to exchangeable density estimation without resorting to averaging over all possible permutations. We achieve new state-of-the-art performance on point cloud and image set modeling.

scholarly journals On the notion of similarity

2018 ◽  
Vol 26 (3) ◽  
Author(s):  
Vanda Božičević
Keyword(s):  
Feature Matching ◽  
Operational Definition ◽  
Common Features ◽  
Family Resemblances ◽  
Definition Of ◽  
Theories Of Meaning

After stressing the importance of the notion of similarity for the theories of meaning, the author discusses the definition of similarity as 'feature matching' and proves it inadequate, offering another operational definition of similarity derived from late Wittgenstein’s idea of 'family resemblances'. Similarity is understood as a 'perceived' pattern of relation correspondences that precedes the abstraction of common features and cannot be reduced to it.

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