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1
Content available Area collapse algorithm computing new curve of 2D geometric objects
Buczek M. M.
Geodesy and Cartography
|
2017
|
Vol. 66, no. 1
23--44
EN
The processing of cartographic data demands human involvement. Up-to-date algorithms try to automate a part of this process. The goal is to obtain a digital model, or additional information about shape and topology of input geometric objects. A topological skeleton is one of the most important tools in the branch of science called shape analysis. It represents topological and geometrical characteristics of input data. Its plot depends on using algorithms such as medial axis, skeletonization, erosion, thinning, area collapse and many others. Area collapse, also known as dimension change, replaces input data with lower-dimensional geometric objects like, for example, a polygon with a polygonal chain, a line segment with a point. The goal of this paper is to introduce a new algorithm for the automatic calculation of polygonal chains representing a 2D polygon. The output is entirely contained within the area of the input polygon, and it has a linear plot without branches. The computational process is automatic and repeatable. The requirements of input data are discussed. The author analyzes results based on the method of computing ends of output polygonal chains. Additional methods to improve results are explored. The algorithm was tested on real-world cartographic data received from BDOT/GESUT databases, and on point clouds from laser scanning. An implementation for computing hatching of embankment is described.
2
Content available remote Application of the 3D objects surface shape analysis algorithms in biomedical engineering
Matan M.
Czasopismo Techniczne. Nauki Podstawowe
|
2014
|
R. 111, z. 2-NP
81--98
EN
The paper describes a concept of measuring possible error estimation and later the decomposition of the predefined model object into convex areas ECD (Exact Convex Decomposition) in order to find a solution to the problem of cavities location with the use of three-dimensional µ-tomography image of the tooth. Such an approach will enable the improvement of automatic cavities detection methods in the future. The paper is also concerned with the problem of a precise object acquisition and estimation of the error value during execution of automatic detection methods.
PL
Publikacja opisuje koncepcje pomiaru możliwego błędu wraz z dekompozycja predefiniowanego modelu obiektu do obszaru wypukłego z użyciem metod ECD (precyzyjnej dekompozycji wypukłej) w celu znalezienia rozwiązania problemu ubytków w zębach z wykorzystaniem trójwymiarowej tomografii obrazu zęba. Wykorzystanie tomografu i metod ECD pozwoli w przyszłości poprawić metody automatycznej detekcji ubytków. W publikacji również rozważany jest problem precyzyjnej akwizycji obiektu z szacowaniem błędu podczas wykonywania metod detekcji automatycznej.
3
Przewidywanie momentu pękania i analiza kształtu wyrobu w procesie cięcia z wykorzystaniem metody doświadczalnej i numerycznej
Świłło S., Czyżewski P.
Prace Naukowe Politechniki Warszawskiej. Mechanika
|
2013
|
z. 253
33--38
PL
Przedstawione zostały przez autorów wyniki pomiarów doświadczalnych i obliczeń numerycznych dla ciętej aluminiowej blachy o grubości 1 mm. W pracy przedstawiono wyniki dla jednej wartości luzu. Pomiary doświadczalne zrealizowane zostały na w pełni automatycznym stanowisku pomiarowym. Zaproponowane zostało rozwiązanie dotyczące wykorzystania metody obróbki obrazu (optical flow) do rozpoznania pól przemieszczeń. Zaprezentowana została kinematyka procesu w odniesieniu do pomiaru odkształceń oraz identyfikacja zjawisk ograniczających tj.: zadzior, ugięcie, tworzenie się stref rozdzielenia materiału. W badaniach doświadczalnych wykorzystano układ wizyjny umożliwiający monitorowanie przebiegu procesu cięcia. Zaprezentowano wyniki odkształceń i wielkości geometryczne pomiarów próbki w trakcie pękania i po rozdzieleniu dla doświadczenia i MES.
EN
The authors presents an experimental and numerical (FEM) results of 1 mm thick sheet metal aluminium at the planar blanking process, where specific clearance was used in the designed, fully automated apparatus. A new approach for the crack propagation visualization based on digital image processin technique (optical flow method) has been proposed. The presented results for the eperiment includes strain measurment, as well as geometrical investigation for the limiting factors. In the experimental approach a vision based apparatus were utilized. Finally, the experimental and numerical results has been combined and presented.
4
Content available Application of shape analysis to the assessment of geometrical properties of grains in the selected species of spring cereals
Borusiewicz Andrzej, Drożyner Paulina
Machine Graphics and Vision
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2013
|
Vol. 22, No. 1/4
3--15
EN
The competition in many branches of industry including agriculture has grown as a result of Polish access to the European Union. It resulted in the intense research development in order to intensify production processes and improve the quality of the final product. One of the methods which might be helpful in this process is the shape analysis. This method makes it possible to measure selected properties of materials in a very precise way. The paper presents the possibilities of computer analysis in the research of grain geometrical features of 128 species of cereals. The program ImageJ was used. It enabled us to define surface, perimeter, width, height and circular projection of every caryopsis. Shape analysis also helps to define basic values of the tested features of caryopsis species. Significant differences between the shape of tested cereals species were indicated. However, significant differences between varieties of the same species were not found. Barley grain had the largest average surface while rye grain had the smallest one. Winter barley grain had the largest perimeter and spring wheat had the smallest one. Oat was characterized by the longest average length while spring wheat had the smallest one. Winter barley had the largest grain width and rye had the smallest one. Spring wheat grain is the most circular while oat grain is the less circular one. Taking into consideration the data mentioned above, one can use them in the production of equipment and machines used for seed planting, selection, segregation of cereal seeds both in agriculture as well as in agricultural and food processing industry.
5
Wybrane problemy wizyjnej analizy parametrów geometrycznych oraz właściwości powierzchniowych próbki dla oceny typu koksu metodą Gray-Kinga
Zając J., Karliński M., Małkiński W.
Elektronika : konstrukcje, technologie, zastosowania
|
2012
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Vol. 53, nr 8
60-64
PL
W artykule przedstawiono strukturę układu akwizycji obrazów próbki, umożliwiającego pomiar parametrów geometrycznych oraz analizę właściwości powierzchniowych próbki koksu. Dla oceny kształtu próbki wyznaczany jest wektor cech podstawowych, na który składają się: pole powierzchni przekroju, średnia szerokość, odchylenie standardowe szerokości, maksymalna i minimalna szerokość próbki. Wprowadzono także dodatkowe metody oceny kształtu próbki, oparte na analizie porównawczej wykresów projekcji oraz histogramów szerokości próbki. Właściwości powierzchniowe próbki oceniano na podstawie analizy histogramów jasności. Metodę oceny kształtu oraz struktury powierzchni próbki zastosowano do oznaczania typu koksu metodą Gray-Kinga.
EN
The article presents the image acguisition system for measurement of geometric parameters and surface analysis of the coke sample. The vector of basic geometric features of sample, such as: cross-section area, mean width, standard deviation of width, maximum and minimum width of sample is calculated. Some additional methods of shape analysis, based on comparison of width projection and width histogram graphs are introduced. Classification of surface features of the coke sample is based on analysis of brightness histogram graphs. The method of sample's shape and surface analysis is applied for the coke type classification using the Gray-King method.
6
Content available Nowe algorytmy analizy kształtu kropli w pomiarach napięcia powierzchniowego oraz kąta zwilżania metali w wysokich temperaturach
Koszmider T., Bąkała M.
Automatyka / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
|
2009
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T. 13, z. 3/1
901-909
PL
W niniejszym artykule przedstawiono nowe algorytmy analizy kształtu kropli metali. Dotyczą one wykorzystania metod przetwarzania i analizy obrazów cyfrowych w procesie pomiaru kąta zwilżania oraz napięcia powierzchniowego materiałów znajdujących się w wysokich temperaturach.
EN
New metal's drop shape analysis algorithms are presented in this paper. They concern utilization of digital image processing and analysis methods in process of wetting tension and contact angle measurements at high temperatures.
7
Content available remote Skeletal curves of 3D astrocyte samples
Klette G.
Machine Graphics and Vision
|
2008
|
Vol. 17, No. 1/2
105-129
EN
The paper discusses the concept of simple (and non-simple) elements for the generation of topologic skeletons, their transformation into abstract curve graphs, and the analysis of such graphs. The definition of a branching index of a point on a curve is fundamental in curve theory (in Euclidean space), and leads to important subjects of curve analysis. This paper derives analogous notions, such as branching index, branch element, and junction, for digital curves, which allow us to introduce new concepts for analyzing complex digital curves in a 3D space. The paper provides new theoretical insights, and also discusses an application project (the description of astrocytes in 3D confocal images of human brain tissue). This work was originally initiated by a particular research project at the Medical School of The University of Auckland. Medical experts developed the hypothesis that features of astrocytes in confocal volume scans are useful for defining states between normal and abnormal tissue. The calculation of skeletal curves, as proposed and studied in this paper, provides a valuable tool for calculating such features.
8
Content available remote Syntactic segmentation of function graph type of curves
Bielecka M.
Machine Graphics and Vision
|
2007
|
Vol. 16, No. 1/2
39-55
EN
In this paper structural analysis of patterns being a special type of curves is presented. The recognized objects are segmented according to their structural properties into primitive patterns representing generic shapes. Then, an algebraic formula describing the structure of the analyzed curve is created. The description is unique.
9
Pomiar kształtu i wielkości cząstek : automatyczna analiza obrazu
Arcichowski P.
LAB Laboratoria, Aparatura, Badania
|
2006
|
R. 11, nr 4
12-16
10
Content available Metoda opisu brył przestrzennych z użyciem regułowej reprezentacji wiedzy
Turek M.
Automatyka / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
|
2006
|
T. 10, z. 3
571-578
PL
Artykuł prezentuje metodę przetwarzania obiektów z przestrzeni trójwymiarowej z wykorzystaniem, jako formy pośredniej struktur analogicznych do wiedzy bazującej na regułach. Zakodowanie niezbędnych do analizy brył informacji w takim formacie umożliwi redukcję ilości danych podlegających dalszej obróbce. Zaproponowana zostanie transformata, która będzie w stanie przeprowadzić zadaną bryłę (siatkę 3D) w opisywany zbiór reguł. Generalnie rzecz ujmując projektowana notacja ma na celu wychwycenie specjalnie wyselekcjonowanych punktów kluczowych każdej bryły oraz relacji między tymi punktami. Umożliwi to uproszczoną i szybką analizę brył w niektórych kierunkach, takich jak gabaryty bryły, czy selekcja komponentów, na które można ją naturalnie podzielić. Wynik analizy zawierał będzie informacje, mogące służyć do rozpoznawania bryły, obudowywania jej inną siatką (np. obrazującą tkaninę), czy szybkiej redukcji fragmentów bryły istotnej przykładowo przy renderowaniu w sporej odległości od obserwatora (z utratą detali).
EN
The article will discuss how to alternatively represent reduced information about 3D polygon meshes. It will propose a transformation able to convert provided 3D mesh into especially designed knowledge format. That format could be described as similar to a rule-based data. Each knowledge base will concentrate knowledge rules - with terms and conclusion specified. Each term will correspond to a point inside 3D mesh - considered by the transformation as important one. As the knowledge base is established a further part of analysis could be made. That part will just use achieved knowledge base as the only data source - providing information about mesh object dimensions, fragmentation or mesh simplification (alternate to mesh polygon reduction technique). The knowledge base can be easily stored, processed quickly, merged or manually edited - mostly because it is much smaller and perspicuous than a corresponding 3D mesh object.
11
Content available remote Picture languages in machine understanding of medical vizualization
Ogiela M. R., Tadeusiewicz R.
Machine Graphics and Vision
|
2005
|
Vol. 14, No. 1
71-82
EN
This paper presents theoretical fundamentals and application of context-free and graph languages for cognitive analysis of selected medical visualization. It shows new opportunities for applying these methods automatic understanding of semantic contents of images in intelligent medical information system. A successful extraction of the crucial semantic content of medical image may contribute considerably to the creation of new intelligent cognitive systems, or medical computer vision systems. Thanks to the new idea of cognitive resonance between a stream of the data extracted from the image using linguistic methods, and expectations following from the language representation of the medical knowledge, it is possible to understand the subject-oriented content of the visual data. This article shows that structural techniques of soft-computing may be applied in automatic classification and machine perception based on semantic pattern content in order to determine the semantic meaning of the patterns.
12
Content available 3D modelling and segmentation with discrete curvatures
Bac A., Daniel M., Maltret J. - L.
Journal of Medical Informatics & Technologies
|
2005
|
Vol. 9
13--24
EN
Recent concepts of discrete curvatures are very important for Medical and Computer Aided Geometric Design applications. A first reason is the opportunity to handle a discretisation of a continuous object, with a free choice of the discretisation. A second and most important reason is the possibility to define second-order estimators for discrete objects in order to estimate local shapes and manipulate discrete objects. There is an increasing need to handle polyhedral objects and clouds of points for which only a discrete approach makes sense. These sets of points, once structured (in general meshed with simplexes for surfaces or volumes), can be analysed using these second-order estimators. After a general presentation of the problem, a first approach based on angular defect, is studied. Then, a local approximation approach (mostly by quadrics) is presented. Different possible applications of these techniques are suggested, including the analysis of 2D or 3D images, decimation, segmentation... We finally emphasise different artefacts encountered in the discrete case.
13
Content available An automatic footshape plantograms analysis based on a new shape-measure
Kocjan K., Kotarski W.
Journal of Medical Informatics & Technologies
|
2004
|
Vol. 8
II15--20
EN
In this note we present a method for recognition of flatfoot abnormality with the help of some new shape-measure describing numerically this abnormality efficient enough. The proposed measure can be easily implemented and used for automatic flatfoot level diagnosis. Experiments carried out on a number of the plantograms, analysed using the computer programme prepared by first of the authors, proved the usefulness of this new approach.
14
Content available remote Kwalifikacja obszarów wymagających scalenia gruntów realizowana w systemie ekspertowym
Eckes K.
Roczniki Geomatyki
|
2003
|
T. 1, z. 1
117-122
PL
Kwalifikacja obszarów wymagających scalenia, dokonywana z udziałem czynnika ludzkiego, jest wprawdzie czynnością prostą, jednak czynność ta może być obarczona błędami osobowymi operatora studiującego obraz mapy katastralnej. Konieczne jest zatem poszukiwanie metod ograniczających czynnik ludzki. Rolę taką spełniają systemy ekspertowe. W niniejszej pracy zostały przedstawione algorytmy ekspertowe kwalifikacji działek o wydłużonym kształcie oraz grupowania tych działek w kompleksy. Algorytmy te stanowią elementy integracji systemu informacji przestrzennej i systemu ekspertowego. Utworzony w ten sposób zintegrowany system może wspomagać pracę ludzką i czynić ją łatwą i wiarygodną.
EN
Classification of areas which require consolidation, made by traditional methods based on cadastral map studies, is a simple activity but limited by the operator.s personal errors. Therefore, it is necessary to seek methods limiting participation of the human factor. This role can be fulfilled by expert systems. In this paper expert algorithms are proposed for classification of plots with elongated shape and grouping them into complexes for consolidation process. These algorithms constitute elements of an integration of a spatial information system and an expert system. The integrated system established this way supports human work and makes it easier, faster and more reliable.
15
Content available Blood cells analysis based on simple geometrical shape descriptors
Kocjan K., Kotarski W., Widuch S.
Journal of Medical Informatics & Technologies
|
2002
|
Vol. 3
MI207--212
EN
In the paper we present some results concerning application of simple shape parameters that are successfully used to distinguish between normal and pathological blood cells. All descriptors are based on shape area and its perimeter. We use five parameters that are automatically calculated for objects pointed out in the analyzed image with the help of our software. The experiments performed on the same set of tested images as in [3] let us draw the same conclusions as those reported in [3] where fractal analysis to shape has been used.
16
Shape analysis of blood cells based on fractal dimension
Kotarski W., Widuch S.
Journal of Medical Informatics & Technologies
|
2001
|
Vol. 2, Part. 1
MI177--MI182
EN
The paper presents some results concerning application of the fractal approach to analysis of shape of blood cells. Using the software by Kindratenko [4] the fractal dimension and other simple geometrical parameters of normal and pathological blood cells have been calculated. The investigation aproved that the fractal dimension and the perimeter of abnormal blood cells differ significantly from normal ones.
17
Content available remote Recognition of cartographic symbols based on a structural model of a shape
Stąpor K.
Machine Graphics and Vision
|
1999
|
Vol. 8, No. 1
129-142
EN
This paper presents a method for recognition of cartographic symbols that is based on a structural model of a general 2D-curve. The presented method utilizes an algebraic description of a curve structure described in [7]. Feature extraction is based in the vectorized skeleton generated by the non-pixelwise thinning algorithm, [14]. From such representation, a structural description of a cartographic symbol is obtained. Finding a match between a model and a given, unknown 2D-shape, is performed through the devised, hybrid procedure, consisting of the structural matching algorithm with followed distance calculation in a parameter space. Experimental results shoen that the method gives satisfying recognition rates.
18
Content available remote A vectorized thinning algorithm for handwritten symbols recognition
Stąpor K.
Machine Graphics and Vision
|
1999
|
Vol. 8, No. 3
341-352
EN
In this paper a non-pixelwise thinning algorithm of binary line images, called vectorized thinning is proposed. The praesented algorithm produces a skeleton of a 2D-object which is performed in three steps: 1) links finding and simple region extraction, 2) complex region extraction and multiple points finding, 3) transformation into vectorized skeleton. As opposed to other thinning algorithms, the obtained skeleton is yet in vector from, particularly suitable for feature extraction in the cartographic symbol recognition from scanned, geodesic maps, with much better results than using other, pixelwise thinning methods ([17]). The main advantages of the proposed thinning algorithm lie in better extraction of multiple points representing corners, branch or crossing regions of 2D objects, and less sensitivity to a boundary noise which is one of the main problems in pixelwise thinning algorithms.
19
Content available remote An image processing based study of the bone erosion process in osteoporosis using radiographic images : a shape metric approach
Majumdar D., Bhattacharya M.
Image Processing & Communications
|
1999
|
Vol. 5, no 2
39-55
EN
An investigation of a class of metabolic bone diseases called osteoporosis which is a very common bone disorder resulting a major disability is carried out with radiographic image modality for diagnostics and therapeutic planning. Based on a mathematical theory of shape authors developed a methodology to compute: (a) an erosion factor for different cases of osteoporosis; (b) a gradation of the disease so that doctor make some quantitative assessment and decide if the disorder can be treated conservatively or surgically.
20
Structural/syntactic methods in perceptual organization of shape modelling and analysis
Jakubowski R., Stąpor K.
Archiwum Informatyki Teoretycznej i Stosowanej
|
1999
|
T. 11, z. 2
133-155
EN
The described method for 3D-shape modelling and analysis represents a model-based approach to object representation and recognition, in which model of a 3D-shape is composed of its graph representation which is based on a structural model of a 2D shape. In the presented method laws of perceptual organization (proximity, continuation, symmetry, closure) are applied in the process of primitive detection and grouping of shape features. The constructed feature knowledge base contains models, that means a set of graph representations of objects together with the minimal representations of their sweep contours in the form of context-free grammars designating them. During perceptual modelling of a 3D object its graph representation is constructed automatically which enables automated analysis and recognition of a modelled 3D object.
PL
W pracy przedstawiona jest metoda strukturalno-syntaktycznej reprezentacji oraz analizy kształtów 3D, wykorzystująca podstawowe prawa perceptualnej organizacji, takie jak: bliskość, domknięcie, symetrię w procesie detekcji oraz modelowania kształtów. Prezentowana metoda jest opartym na modelu podejściem do reprezentacji i rozpoznawania i wykorzystuje dla reprezentacji obiektów 3D uogólniony model sweepingu, który z kolei zdefiniowany jest w oparciu o strukturalny model 2D kształtu. Skonstruowana baza wiedzy o kształtach zawiera modele obiektów składające się z grafowej reprezentacji 3D obiektów modelowanych za pomocą operacji sweepingu wraz z minimalna reprezentacją konturów 2D tychże operacji sweepingu w formie bezkonteksowych gramatyk je opisujących. W procesie perceptualnego modelowania automatycznie konstruowana jest grafowa reprezentacja modelowanego 3D kształtu, co umożliwia automatyczną analizę modelowanego obiektu, obejmującą następujące kroki: extrakcję cech, perceptualne grupowanie, uzgadnianie z modelem oraz weryfikację. Uzgadnianie oparte jest o izomorfizm grafów oraz syntaktyczne rozpoznawanie 2D kształtów.
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