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1

Basic mechanisms of Brownian string analysis and manipulation

Bartyzel K.

Journal of Applied Computer Science

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2018

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Vol. 26, nr 2

7--22

EN

The paper presents the possibilities of using Brownian Strings as an example of Active Contour Model for linguistic description of objects in an image. Having only a notation composed of a combination of characters RULD we can calculate the statistics of the object, such as its surface area, width and height, centroid, and even image moments. The part is thoroughly discussed. The requirements for a combination of characters RULD to be called a Brownian contour are also presented and analysed carefully.

2

Potential Contour Ensembles

Tomczyk A.

Schedae Informaticae

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2015

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Vol. 24

113--121

EN

In the paper a contour ensemble image segmentation concept is presented. It bases on the previously observed relationship between contours and classifiers. Because of the specificity of the active contour segmentation the method requires a special procedure to obtain ensemble members with desired properties. In this work it is achieved by early stopping of randomized optimization algorithm. The results of the method are illustrated with a practical problem of heart ventricle segmentation by means of active potential contours. Automatically found contours may be of use in a process of pulmonary embolism diagnosis.

3

Application of active contours with expert knowledge to heart ventricle segmentation

Tomczyk A.

Journal of Applied Computer Science

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2013

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Vol. 21, nr 2

181--194

EN

Automatic heart ventricle segmentation in CT heart images can be an element of system supporting pulmonary embolism diagnosis. To solve that problem in this paper an application of two classical active contour models, snakes and geometric active contours, is proposed. The prepared implementation uses the unified model of those techniques which allows to define forces acting upon a contour only once. The nature of the images causes that the process of force construction requires additional expert knowledge since using only the information visible in the image satisfactory results cannot be obtained.

4

Metoda aktywnych konturów w segmentacji znaków na tablicach rejestracyjnych

Półrolniczak E.

Pomiary Automatyka Kontrola

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2012

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R. 58, nr 2

176-179

PL

Rozpoznawanie tablic rejestracyjnych jest w obecnych czasach jednym z bardziej aktualnych zagadnień. Cały proces przebiega od pozyskania zdjęcia pojazdu z tablicą rejestracyjną, poprzez ekstrakcję samej tablicy, do wydzielenia kolejnych znaków alfanumerycznych tablicy i ich rozpoznawania. W niniejszym artykule zaproponowano skuteczne rozwiązanie zagadnienia wchodzącego w proces wyodrębniania znaków z tablic rejestracyjnych. W szczególności chodzi o etap segmentacji znaków alfanumerycznych dla potrzeb systemu rozpoznawania. Proponuje się tutaj metodę aktywnych konturów, która, jak pokazano, daje doskonałe rezultaty.

EN

Recognition of license plates is one of the topical issues nowadays. The whole process proceeds from acquisition of a vehicle picture with the number plate, through extraction of the license plate region, to separation of consecutive alphanumerical characters of the number plate and their recognition. In the paper an efficient solution of the issue being part of the process of signs isolation from number plates is proposed. This particularly concerns the stage of segmentation of alphanumerical signs for needs of a recognition system. The method of active contours giving excellent results is proposed. Segmentation of licence plates has been chosen as an example of real life application of the presented algorithm. It seems that the license plate images contain much more noise than images of written texts. The algorithm performance was influenced by weather, air clarity, time of day, and other factors. The method was compared with the less complex SRM method and showed better performance on the same database.

5

Hand gesture recognition based on free-form contours and probabilistic inference

Kasprzak W., Wilkowski A., Czapnik K.

International Journal of Applied Mathematics and Computer Science

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2012

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Vol. 22, no. 2

437-448

EN

A computer vision system is described that captures color image sequences, detects and recognizes static hand poses (i.e., 'letters') and interprets pose sequences in terms of gestures (i.e., 'words'). The hand object is detected with a double-active contour-based method. A tracking of the hand pose in a short sequence allows detecting 'modified poses', like diacritic letters in national alphabets. The static hand pose set corresponds to hand signs of a thumb alphabet. Finally, by tracking hand poses in a longer image sequence, the pose sequence is interpreted in terms of gestures. Dynamic Bayesian models and their inference methods (particle filter and Viterbi search) are applied at this stage, allowing a bi-driven control of the entire system.

6

Automatic estimation of the intima-media thickness of the common carotid artery

Turcza R., Zieliński T. P., Lay-Ekuakille A.

Elektronika : konstrukcje, technologie, zastosowania

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2010

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Vol. 51, nr 3

109-113

EN

In this paper we propose efficient method for automatic estimation of intima and media boundary of common carotid artery (CCA) based on USG image analysis. The distance between intima and media is called intima-media thickness (IMT) and is used to predict cardiovascular events like myocardial infarction and stroke. At present, it is measured by manual segmentation of USG image by physician. Automatic estimation of IMT by freeing physician from this tedious work should speed the process and assure higher reproducibility. The proposed algorithm involves USG image denoising by nonlinear diffusion filtering and iterative image segmentation by modified active contour method with suitable energy function.

PL

W artykule zaproponowano efektywną metodę do automatycznej estymacji położenia brzegów błony wewnętrznej i środkowej tętnicy szyjnej, bazującą na analizie obrazu USG. Odległość pomiędzy brzegami tych błon nosi nazwę grubości intima - media i jest wykorzystywana do prognozowania ryzyka sercowo - naczyniowego (zawałów, udarów). W chwili obecnej grubość intima - media jest mierzona drogą ręcznego podziału na części obrazu USG tętnicy szyjnej przez lekarza. Automatyczna estymacja tej grubości uwolni lekarza od tego czasochłonnego zajęcia i zapewni większą powtarzalność pomiaru. Algorytm obliczeniowy zaproponowany w artykule wykorzystuje nieliniową filtrację dyfuzyjną do skutecznego odszumiania obrazu USG oraz iteracyjną segmentację obrazu za pomocą zmodyfikowanej metody aktywnych konturów, wykorzystującej odpowiednio dobraną funkcję energii.

7

Models, algorithms and applications in vascular image segmentation

Orkisz M., Valencia L. F., Hoyos M. H.

Machine Graphics and Vision

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2008

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Vol. 17, No. 1/2

5-33

EN

A synthesis of the authors' projects in the field of 3D vascular image processing in the last decadeis provided. This work was motivated by the following applications: display improvement, extraction of geometrical measurements, acquisition optimization, stent-pose planning, phantom generation, blood-flow simulations. The methods are often dependent on the imaging modality and/or on the anatomic region. They involve both: low-level models of intensity patterns and profiles, and higher-level models of cylindrical shapes. Amongst the various algorithms used, recursive tracking and fast-marching level-sets are emphasized. Critical analysis of each model and algorithm is carried out. Problems that remain open, and perspectives associated with the progress of the image acquisition techniques, are listed.

8

Segmentation of breast cancer fine needle biopsy cytological images

Hrebień M., Steć P., Nieczkowski T., Obuchowicz A.

International Journal of Applied Mathematics and Computer Science

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2008

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Vol. 18, no 2

159-170

EN

This paper describes three cytological image segmentation methods. The analysis includes the watershed algorithm, active contouring and a cellular automata GrowCut method. One can also find here a description of image pre-processing, Hough transform based pre-segmentation and an automatic nuclei localization mechanism used in our approach. Preliminary experimental results collected on a benchmark database present the quality of the methods in the analyzed issue. The discussion of common errors and possible future problems summarizes the work and points out regions that need further research.

9

On the segmentation of the Comet Assay images

Smolka B., Szczepański M., Świerniak A., Palus H., Plataniotis K. N.

Journal of Medical Informatics & Technologies

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2001

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Vol. 2, Part. 1

MI29--MI39

EN

The single cell gel electrophoresis, called Comet Assay is a microelectrophoretic technique of direct visualization of DNA damage at the cell level. In the comet assay, the cells suspended in an agarose gel on a microscope slide are subjected to lysis, unwinding of DNA and electrophoresis. After staining with fluorescent DNA binding dye, cells with DNA damage display increased migration of genetic material from the cell nucleus. Under the influence of weak, statics electric field, charged DNA migrates away from the nucleus forming a so called comet. The damage is quantified by measuring the amound of the genetic material, which migrates from the nucleus to form the comet tail. The foremost advantage of the comet assay is that it analyses individual cells, thus allowing the measurement of the heterogeneity of response within a cell population. In this paper we present three novel method of the comet tail and head extraction.