Geometric Shape Characterisation Based on a Multi-Sweeping Paradigm

The characterisation of geometric shapes produces their concise description and is, therefore, important for subsequent analyses, for example in Computer Vision, Machine Learning, or shape matching. A new method for extracting characterisation vectors of 2D geometric shapes is proposed in this paper...

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Main Authors: Borut Žalik , Damjan Strnad , David Podgorelec , Ivana Kolingerová , Andrej Nerat , Niko Lukač , Štefan Kohek , Luka Lukač 
Format: Article
Language:English
Published: MDPI AG 2023-06-01
Series:Symmetry
Subjects:
Online Access:https://www.mdpi.com/2073-8994/15/6/1212
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author Borut Žalik 
Damjan Strnad 
David Podgorelec 
Ivana Kolingerová 
Andrej Nerat 
Niko Lukač 
Štefan Kohek 
Luka Lukač 
author_facet Borut Žalik 
Damjan Strnad 
David Podgorelec 
Ivana Kolingerová 
Andrej Nerat 
Niko Lukač 
Štefan Kohek 
Luka Lukač 
author_sort Borut Žalik 
collection DOAJ
description The characterisation of geometric shapes produces their concise description and is, therefore, important for subsequent analyses, for example in Computer Vision, Machine Learning, or shape matching. A new method for extracting characterisation vectors of 2D geometric shapes is proposed in this paper. The shape of interest, embedded into a raster space, is swept several times by sweep-lines having different slopes. The interior shape’s points, being in the middle of its boundary and laying on the actual sweep-line, are identified at each stage of the sweeping process. The midpoints are then connected iteratively into chains. The chains are filtered, vectorised, and normalised. The obtained polylines from the vectorisation step are used to design the shape’s characterisation vector for further application-specific analyses. The proposed method was verified on numerous shapes, where single- and multi-threaded implementations were compared. Finally, characterisation vectors, among which some were rotated and scaled, were determined for these shapes. The proposed method demonstrated a good rotation- and scaling-invariant identification of equal shapes.
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spelling doaj.art-4ec94b895ca144439e3869b5dc6d08fd2023-11-18T12:51:01ZengMDPI AGSymmetry2073-89942023-06-01156121210.3390/sym15061212Geometric Shape Characterisation Based on a Multi-Sweeping ParadigmBorut Žalik 0Damjan Strnad 1David Podgorelec 2Ivana Kolingerová 3Andrej Nerat 4Niko Lukač 5Štefan Kohek 6Luka Lukač 7Faculty of Electrical Engineering and Computer Science, University of Maribor, Koroška cesta 46, SI-2000 Maribor, SloveniaFaculty of Electrical Engineering and Computer Science, University of Maribor, Koroška cesta 46, SI-2000 Maribor, SloveniaFaculty of Electrical Engineering and Computer Science, University of Maribor, Koroška cesta 46, SI-2000 Maribor, SloveniaDepartment of Computer Science and Engineering, University of West Bohemia, Technická 8, 306 14 Plzeň, Czech RepublicFaculty of Electrical Engineering and Computer Science, University of Maribor, Koroška cesta 46, SI-2000 Maribor, SloveniaFaculty of Electrical Engineering and Computer Science, University of Maribor, Koroška cesta 46, SI-2000 Maribor, SloveniaFaculty of Electrical Engineering and Computer Science, University of Maribor, Koroška cesta 46, SI-2000 Maribor, SloveniaFaculty of Electrical Engineering and Computer Science, University of Maribor, Koroška cesta 46, SI-2000 Maribor, SloveniaThe characterisation of geometric shapes produces their concise description and is, therefore, important for subsequent analyses, for example in Computer Vision, Machine Learning, or shape matching. A new method for extracting characterisation vectors of 2D geometric shapes is proposed in this paper. The shape of interest, embedded into a raster space, is swept several times by sweep-lines having different slopes. The interior shape’s points, being in the middle of its boundary and laying on the actual sweep-line, are identified at each stage of the sweeping process. The midpoints are then connected iteratively into chains. The chains are filtered, vectorised, and normalised. The obtained polylines from the vectorisation step are used to design the shape’s characterisation vector for further application-specific analyses. The proposed method was verified on numerous shapes, where single- and multi-threaded implementations were compared. Finally, characterisation vectors, among which some were rotated and scaled, were determined for these shapes. The proposed method demonstrated a good rotation- and scaling-invariant identification of equal shapes.https://www.mdpi.com/2073-8994/15/6/1212computer scienceimage analysiscomputational geometrylocal reflection symmetry
spellingShingle Borut Žalik 
Damjan Strnad 
David Podgorelec 
Ivana Kolingerová 
Andrej Nerat 
Niko Lukač 
Štefan Kohek 
Luka Lukač 
Geometric Shape Characterisation Based on a Multi-Sweeping Paradigm
Symmetry
computer science
image analysis
computational geometry
local reflection symmetry
title Geometric Shape Characterisation Based on a Multi-Sweeping Paradigm
title_full Geometric Shape Characterisation Based on a Multi-Sweeping Paradigm
title_fullStr Geometric Shape Characterisation Based on a Multi-Sweeping Paradigm
title_full_unstemmed Geometric Shape Characterisation Based on a Multi-Sweeping Paradigm
title_short Geometric Shape Characterisation Based on a Multi-Sweeping Paradigm
title_sort geometric shape characterisation based on a multi sweeping paradigm
topic computer science
image analysis
computational geometry
local reflection symmetry
url https://www.mdpi.com/2073-8994/15/6/1212
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