Image Key Point Matching by Phase Congruency

Fabric shape style is one of the most important conditions in textile appearance evaluation, and also the main factor influences customer purchasing psychology. At first, the previous fabric shape style evaluation methods are classified and summarized, measurement and evaluation method discussed from tactic and dynamic aspects. Then, companied with computer vision principle, a non-contact method for measuring fabric shape style was put forward. In this method, two high-speed CCD cameras were used to capture fabric movement dynamically, fabric sequences image were obtained in this process. Used the image processing technology include pretreatment and feature point matching to get 3D motion parameters, it can provide data supports for shape style evaluation.

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Closed-Form Expressions for Numerical Evaluation of Self-Impedance Terms Involved on Wire Antenna Analysis by the Method of Moments

Electronics ◽

10.3390/electronics10111316 ◽

2021 ◽

Vol 10 (11) ◽

pp. 1316

Author(s):

Carlos-Ivan Paez-Rueda ◽

Arturo Fajardo ◽

Manuel Pérez ◽

Gabriel Perilla

Keyword(s):

Numerical Integration ◽

Method Of Moments ◽

Computing Time ◽

Basis Functions ◽

Wire Antenna ◽

Complex Geometries ◽

Point Matching ◽

Piecewise Constant ◽

Matching Procedure ◽

Time Required

This paper proposes new closed expressions of self-impedance using the Method of Moments with the Point Matching Procedure and piecewise constant and linear basis functions in different configurations, which allow saving computing time for the solution of wire antennas with complex geometries. The new expressions have complexity O(1) with well-defined theoretical bound errors. They were compared with an adaptive numerical integration. We obtain an accuracy between 7 and 16 digits depending on the chosen basis function and segmentation used. Besides, the computing time involved in the calculation of the self-impedance terms was evaluated and compared with the time required by the adaptative quadrature integration solution of the same problem. Expressions have a run-time bounded between 50 and 200 times faster than an adaptive numerical integration assuming full computation of all constant of the expressions.

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Line and point matching based on the maximum number of consecutive matching edge segment pairs for large viewpoint changing images

Signal Image and Video Processing ◽

10.1007/s11760-021-01959-6 ◽

2021 ◽

Author(s):

Luzi Wang ◽

Yunsheng Qian ◽

Xiangyu Kong

Keyword(s):

Point Matching ◽

Edge Segment

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NSCT and focus measure optimization based multi-focus image fusion

Journal of Intelligent & Fuzzy Systems ◽

10.3233/jifs-202803 ◽

2021 ◽

pp. 1-13

Author(s):

N. Aishwarya ◽

C. BennilaThangammal ◽

N.G. Praveena

Keyword(s):

Simulation Analysis ◽

Structural Information ◽

Research Area ◽

Processing Technique ◽

The Novel ◽

Phase Congruency ◽

Focus Measure ◽

Fused Image ◽

Focus Image ◽

Image Pairs

Getting a complete description of scene with all the relevant objects in focus is a hot research area in surveillance, medicine and machine vision applications. In this work, transform based fusion method called as NSCT-FMO, is introduced to integrate the image pairs having different focus features. The NSCT-FMO approach basically contains four steps. Initially, the NSCT is applied on the input images to acquire the approximation and detailed structural information. Then, the approximation sub band coefficients are merged by employing the novel Focus Measure Optimization (FMO) approach. Next, the detailed sub-images are combined using Phase Congruency (PC). Finally, an inverse NSCT operation is conducted on synthesized sub images to obtain the initial synthesized image. To optimize the initial fused image, an initial decision map is first constructed and morphological post-processing technique is applied to get the final map. With the help of resultant map, the final synthesized output is produced by the selection of focused pixels from input images. Simulation analysis show that the NSCT-FMO approach achieves fair results as compared to traditional MST based methods both in qualitative and quantitative assessments.

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Retinal Blood Vessel Segmentation Using Hybrid Features and Multi-Layer Perceptron Neural Networks

Symmetry ◽

10.3390/sym12060894 ◽

2020 ◽

Vol 12 (6) ◽

pp. 894 ◽

Cited By ~ 1

Author(s):

Nasser Tamim ◽

M. Elshrkawey ◽

Gamil Abdel Azim ◽

Hamed Nassar

Keyword(s):

Blood Vessel ◽

Performance Metrics ◽

Feature Vector ◽

Disease Diagnosis ◽

Processing Technique ◽

Ocular Disease ◽

Multi Layer Perceptron ◽

Phase Congruency ◽

Hybrid Features ◽

Local Intensity

Segmentation of retinal blood vessels is the first step for several computer aided-diagnosis systems (CAD), not only for ocular disease diagnosis such as diabetic retinopathy (DR) but also of non-ocular disease, such as hypertension, stroke and cardiovascular diseases. In this paper, a supervised learning-based method, using a multi-layer perceptron neural network and carefully selected vector of features, is proposed. In particular, for each pixel of a retinal fundus image, we construct a 24-D feature vector, encoding information on the local intensity, morphology transformation, principal moments of phase congruency, Hessian, and difference of Gaussian values. A post-processing technique depending on mathematical morphological operators is used to optimise the segmentation. Moreover, the selected feature vector succeeded in outfitting the symmetric features that provided the final blood vessel probability as a binary map image. The proposed method is tested on three known datasets: Digital Retinal Image for Extraction (DRIVE), Structure Analysis of the Retina (STARE), and CHASED_DB1 datasets. The experimental results, both visual and quantitative, testify to the robustness of the proposed method. This proposed method achieved 0.9607, 0.7542, and 0.9843 in DRIVE, 0.9632, 0.7806, and 0.9825 on STARE, 0.9577, 0.7585 and 0.9846 in CHASE_DB1, with respectable accuracy, sensitivity, and specificity performance metrics. Furthermore, they testify that the method is superior to seven similar state-of-the-art methods.

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Scene Wireframes Sketching for Drones

Proceedings ◽

10.3390/proceedings2181193 ◽

2018 ◽

Vol 2 (18) ◽

pp. 1193

Author(s):

Roi Santos ◽

Xose Pardo ◽

Xose Fdez-Vidal

Keyword(s):

State Of The Art ◽

Point Clouds ◽

Outdoor Environment ◽

Point Matching ◽

3D Point Clouds ◽

Complementary Approach ◽

Straight Line ◽

Scene Representation ◽

Feature Point Matching ◽

3D Scene

The increasing use of autonomous UAVs inside buildings and around human-made structures demands new accurate and comprehensive representation of their operation environments. Most of the 3D scene abstraction methods use invariant feature point matching, nevertheless some sparse 3D point clouds do not concisely represent the structure of the environment. Likewise, line clouds constructed by short and redundant segments with inaccurate directions limit the understanding of scenes as those that include environments with poor texture, or whose texture resembles a repetitive pattern. The presented approach is based on observation and representation models using the straight line segments, whose resemble the limits of an urban indoor or outdoor environment. The goal of the work is to get a full method based on the matching of lines that provides a complementary approach to state-of-the-art methods when facing 3D scene representation of poor texture environments for future autonomous UAV.

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The Bending, Buckling, and Flexural Vibration of Simply Supported Polygonal Plates by Point-Matching

Journal of Applied Mechanics ◽

10.1115/1.3641670 ◽

1961 ◽

Vol 28 (2) ◽

pp. 288-291 ◽

Cited By ~ 51

Author(s):

H. D. Conway

Keyword(s):

Hydrostatic Pressure ◽

Boundary Conditions ◽

Flexural Vibration ◽

Frequency Equation ◽

Numerical Results ◽

Special Technique ◽

Point Matching ◽

Buckling Loads ◽

Simply Supported ◽

Flexural Vibrations

The bending by uniform lateral loading, buckling by two-dimensional hydrostatic pressure, and the flexural vibrations of simply supported polygonal plates are investigated. The method of meeting the boundary conditions at discrete points, together with the Marcus membrane analog [1], is found to be very advantageous. Numerical examples include the calculation of the deflections and moments, and buckling loads of triangular square, and hexagonal plates. A special technique is then given, whereby the boundary conditions are exactly satisfied along one edge, and an example of the buckling of an isosceles, right-angled triangle plate is analyzed. Finally, the frequency equation for the flexural vibrations of simply supported polygonal plates is shown to be the same as that for buckling under hydrostatic pressure, and numerical results can be written by analogy. All numerical results agree well with the exact solutions, where the latter are known.

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