Wyniki wyszukiwania - BazTech

1

Automated and effective content-based mammogram retrieval using wavelet based CS-LBP feature and self-organizing map

Singh V. P., Srivastava R.

Biocybernetics and Biomedical Engineering

|

2018

|

Vol. 38, no. 1

90--105

EN

In this paper, automated, fast and effective content based-mammogram image retrieval system is proposed. The proposed pre-processing steps include automatic labelling-scratches suppression, automatic pectoral muscle removal and image enhancement. Further, for segmentation selective thresholds based seeded region growing algorithm is introduced. Furthermore, we apply 2-level discrete wavelet transform (DWT) on the segmented region and wavelet based centre symmetric-local binary pattern (WCS-LBP) features are extracted. Then, extracted features are fed to self-organizing map (SOM) which generates clusters of images, having similar visual content. SOM produces different clusters with their centres and query image features are matched with all cluster representatives to find closest cluster. Finally, images are retrieved from this closest cluster using Euclidean distance similarity measure. So, at the searching time the query image is searched only in small subset depending upon cluster size and is not compared with all the images in the database, reflects a superior response time with good retrieval performances. Descriptive experimental and empirical discussions confirm the effectiveness of this paper.

2

Novel visual object descriptor using surf and clustering algorithms

Grycuk R.

Journal of Applied Mathematics and Computational Mechanics

|

2016

|

Vol. 15, nr 3

37--46

EN

In this paper we propose a method for object description based on two wellknown clustering algorithms (k-means and mean shift) and the SURF method for keypoints detection. We also perform a comparison of these clustering methods in object description area. Both of these algorithms require one input parameter; k-means (k, number of objects) and mean shift (h, window). Our approach is suitable for images with a non-homogeneous background thus, the algorithm can be used not only on trivial images. In the future we will try to remove non-important keypoints detected by the SURF algorithm. Our method is a part of a larger CBIR system and it is used as a preprocessing stage.

3

New image descriptor from edge detector and blob extractor

Grycuk R., Scherer R., Gabryel M.

Journal of Applied Mathematics and Computational Mechanics

|

2015

|

Vol. 14, nr 4

31--39

EN

In this paper we present a novel approach for image description. The method is based on two well-known algorithms: edge detection and blob extraction. In the edge detection step we use the Canny detector. Our method provides a mathematical description of each object in the input image. On the output of the presented algorithm we obtain a histogram, which can be used in various fields of computer vision. In this paper we applied it in the content-based image retrieval system. The simulations proved the effectiveness of our method.

4

Techniki semantycznego indeksowania obrazów medycznych na przykładzie przestrzennych rekonstrukcji unaczynienia wieńcowego

Trzupek M., Ogiela M. R.

Pomiary Automatyka Kontrola

|

2013

|

R. 59, nr 1

43--46

PL

W artykule zaprezentowano techniki semantycznego indeksowania danych obrazowych w medycznych bazach danych z wykorzystaniem grafowych formalizmów lingwistyki matematycznej. Zaproponowane rozwiązania w głównej mierze predestynowane są do wizualizacji pochodzących z obrazowania CT (przestrzennych rekonstrukcji unaczynienia wieńcowego), niemniej jednak przedstawiona metodologia może również stanowić bazę dla innej klasy obrazów medycznych.

XX

The wide spread of multimedia medical databases has shown that the problem of storing and effectively searching for images containing specific disease cases that are significant for medical diagnostics is still fraught with great difficulties. The paper presents semantic indexing techniques in medical imaging databases using graph-based mathematical linguistic formalisms. The proposed solutions are mainly predestined for visualizations obtained from diagnostic examinations with the use of computed tomography (spatial reconstructions of the coronary vascularisation), but the presented methodology can also be a basis for a different class of medical images. The first section describes the methods and limitations in the context of storing and searching for data in medical databases of contemporary systems. The second section presents the historical background and discusses examples of systems. The third section describes next steps of the proposed methodology, which is additionally shown in Fig. 3. The last section summarizes the proposed solutions in the context of other systems and indicates further research directions. The obtained results confirm the possibility of using the proposed solutions in the specialized medical databases.

5

Classification problem in CBIR

Jaworska T.

Journal of Theoretical and Applied Computer Science

|

2013

|

Vol. 7, nr 2

3--15

EN

At present a great deal of research is being done in different aspects of Content-Based Image Retrieval (CBIR). Image classification is one of the most important tasks in image retrieval that must be dealt with. The primary issue we have addressed is: how can the fuzzy set theory be used to handle crisp image data. We propose fuzzy rule-based classification of image objects. To achieve this goal we have built fuzzy rule-based classifiers for crisp data. In this paper we present the results of fuzzy rule-based classification in our CBIR. Furthermore, these results are used to construct a search engine taking into account data mining.

6

Dopasowywanie obrazów sonarowych w oparciu o metodę informacji wzajemnej

Chorzewska K., Felski A.

Zeszyty Naukowe Akademii Marynarki Wojennej

|

2012

|

R. 53 nr 4 (191)

19-32

PL

Wśród wielu zagrożeń dla współczesnej żeglugi morskiej wymienia się między innymi zagrożenie terroryzmem. Na wodach płytkich może ono przyjmować postać zagrożenia improwizowanymi ładunkami wybuchowymi umieszczanymi na dnie z pokładów dowolnych jednostek, pojawiających się na akwenie w sposób niezauważalny dla kogokolwiek. Jednym z kierunków działań zmierzających do poprawy bezpieczeństwa w tym zakresie jest koncepcja hydroakustycznego systemu ochrony portów, torów wodnych i kotwicowisk. Zakłada ona możliwość szybkiego porównywania obrazów sonarowych z obrazami archiwalnymi, dając podstawy do wykrywania zmian na ochranianym akwenie, przy czym powszechna dostępność technik cyfrowych sugeruje wykonywanie takich poszukiwań w tej właśnie technologii. Porównywanie sonogramów metodami cyfrowej analizy obrazów wymaga w pierwszej kolejności przeprowadzenia ich prawidłowego automatycznego dopasowania. Automatyzacja procesu dopasowania obrazów otwiera dodatkowo perspektywy ich zastosowania w systemach nawigacji porównawczej. W artykule przedstawiono ujęcie tego zagadnienia w sposób właściwy dla technik wyszukiwania obrazów na podstawie zawartości (Content-Based Image Retrieval — CBIR). Wyznaczenie najlepszego dopasowania dwóch sonogramów przeprowadzono w oparciu o metodę maksymalizacji informacji wzajemnej.

EN

Among many threats to the present maritime navigation the terrorism has risen to the rank of one of the most serious. In shallow waters there is a possibility of using the improvised explosive devices which can be placed on the seabed impromptu and imperceptible for anybody from deck of any watercraft or from a harbor quay. One of the proposals to improve the safety in this area is the idea of hydro acoustic surveillance system of ports, fairways and anchorages. It is based on the assumption that sonar images can be quickly compared with archived images leading to detecting changes in the waters protected. Widespread access to digital technologies suggests using them to deal with the problem mentioned. However, to compare sonograms with the digital picture analysis methods requires, first of all, their proper automatic adjustment. The automation of the image-matching process also opens perspectives for using it in systems based on the comparative navigation. The paper presents the approach to the issue based on Content-Based Image Retrieval (CBIR).The Mutual Information method is employed to best match two sonograms.

7

Improving quality of cytological screening in early detection of malignancy associated changes

Piętka B. D., Dulewicz A. M., Kupis P.

Journal of Medical Informatics & Technologies

|

2012

|

Vol. 19

85--91

EN

The paper deals with an image database organization and utilization in computer-aided cytology. To illustrate the idea we take as an example the problem of bladder cancer early detection based on urine cytology. In spite of its diagnostic potential for discovering malignancy associated changes (MAC) at the cell level it seems to be underestimated. There is common view that sensitivity of the method, especially for early cancer stages, is relatively low. We depict here just one but significant direction of our works that aims to support pathologists making the diagnosis more accurate and reliable. The key idea relies on automatic searching for MAC by comparing nuclear chromatin structure of objects in a smear with a collection of sample patterns contained in a pathomorphological image database.

8

Optimized image feature selection using pairwise classifiers

Bazarganigilani M.

Journal of Artificial Intelligence and Soft Computing Research

|

2011

|

Vol. 1, No. 2

147--153

EN

In this paper, we introduce an optimized method to improve the accuracy of content based image retrieval systems (CBIR). CBIR systems classify the images according to low and higher features.In our research, we improve both feature selection and classifier partition of a CBIR system. Results show great performance of our proposed algorithm.

9

Structural Feature-Based Image Hashing and Similarity Metric for Tampering Detection

Tang Z., Wang S., Zhang X., Wei W.

Fundamenta Informaticae

|

2011

|

Vol. 106, nr 1

75-91

EN

Structural image features are exploited to construct perceptual image hashes in this work. The image is first preprocessed and divided into overlapped blocks. Correlation between each image block and a reference pattern is calculated. The intermediate hash is obtained from the correlation coefficients. These coefficients are finally mapped to the interval [0, 100], and scrambled to generate the hash sequence. A key component of the hashingmethod is a specially defined similarity metric to measure the "distance" between hashes. This similarity metric is sensitive to visually unacceptable alterations in small regions of the image, enabling the detection of small area tampering in the image. The hash is robust against content-preserving processing such as JPEG compression, moderate noise contamination, watermark embedding, re-scaling, brightness and contrast adjustment, and low-pass filtering. It has very low collision probability. Experiments are conducted to show performance of the proposed method.

10

An experimental comparison of Extended Gaussian Image and Shape Distributions in 3D shape retrieval

Frejlichowski D.

Pomiary Automatyka Kontrola

|

2010

|

R. 56, nr 8

973-975

EN

The effective retrieval of three-dimensional shapes is a very crucial problem nowadays. It has to be not only efficient but also carried out in reasonable time. The last demand is especially difficult as 3D objects are usually built using lots of data (vertices, patches, etc.). That was the reason for minor interest dedicated few decades ago by scientists to them. At present, this problem became less important, thanks to the advances in computer hardware development. Now, one can find many new applications of 3D models, e.g. in CAD systems, entertainment, virtual reality, biometrics and image retrieval. In order to work with those objects three-dimensional shape descriptors are used. Those algorithms are created to represent objects independently of various problems concerning them, e.g. affine transformations, noise, occlusions. The result of experimental examination of two 3D shape descriptors is provided in the paper. The research was performed using the models from the "Princeton Shape Benchmark" database. This database is very popular in the task of experimental evaluation of 3D shape descriptors. In the paper two methods of that type are explored - Extended Gaussian Image and Shape Distributions - in the problem of 3D shape retrieval.

PL

Skuteczne wyszukiwanie kształtów trójwymiarowych w multimedialnych bazach danych jest istotnym problemem. Musi być ono nie tylko efektywne, ale i wykonywane w rozsądnym czasie. Ten drugi warunek jest szczególnie trudny do spełnienia, ponieważ obiekty 3D są zazwyczaj skonstruowane z użyciem dużej ilości danych (wierzchołki, powierzchnie, itp.). Było to dawniej powodem mniejszego zainteresowania naukowców tym zagadnieniem. Obecnie, problem ten stał się mniej znaczący, dzięki postępowi technicznemu w dziedzinie sprzętu komputerowego. Możemy więc aktualnie znaleźć wiele zastosowań modeli 3D, np. w komputerowo wspomaganym projektowaniu, rozrywce, rzeczywistości wirtualnej, biometrii oraz wyszukiwaniu obrazów. Aby móc pracować z tego typu obiektami stosowane są deskryptory kształtu. Te algorytmy są tworzone po to, by reprezentować obiekty niezależnie od poszczególnych problemów ich dotyczących, np. przekształceń afinicznych, szumu, okluzji. W artykule przedstawiono wyniki porównania eksperymentalnego dwóch deskryptorów kształtu 3D. Badania wykonano z użyciem modeli z bazy "Princeton Shape Benchmark". Baza ta jest bardzo popularna w ocenie deskryptorów kształtu 3D. W artykule dwie metody tego typu są badane - Rozszerzone Obrazy Gaussa oraz Rozkłady Kształtu - w kontekście problemu indeksowania kształtów 3D.

11

Application of a Pathomorphological Image Database in Computer-Aided Cytological Examinations

Piętka B. D., Dulewicz A., Jaszczak P., Kupis P.

Machine Graphics and Vision

|

2010

|

Vol. 19, No. 3

321-337

EN

The paper deals with the problem of early detection of bladder cancer based on non-invasive, voided urine cytological investigations. In spite of the diagnostic potential of the method for discovering malignancy associated changes in cells before they start to form a tumour, cytological tests seem to be underestimated by physicians, as there is a common view that their sensitivity, especially in early stages of the cancer, is relatively low. We depict here just one, but significant, direction of our work that aims to support the cytopathologist in making the diagnosis more accurate and reliable. The key idea relies on classification of adaptive smear objects by searching for similar patterns in a flexible pathomorphological image database using content-based image retrieval technology (CBIR).

12

Reprezentacja kształtu 3D oparta na deskryptorze EGI na potrzeby indeksowania

Frejlichowski D.

Metody Informatyki Stosowanej

|

2009

|

nr 3 (20)

83-89

PL

W niniejszym artykule przedstawiono wyniki wstępnych badań nad problemem opisu kształtów trójwymiarowych z użyciem deskryptora EGI (Extended Gaussian Image). Jest to jeden z popularniejszych algorytmów, którego największą zaletą jest intuicyjność i skuteczność w podstawowych zastosowaniach. W artykule skoncentrowano się na ozpoznawaniu kształtów w kontekście indeksowania tego typu obiektów w multimedialnych bazach danych (CBIR – Content Based Image Retrieval).

EN

The paper presents experimental results on three dimensional shape description and recognition using EGI (Extended Gaussian Image) 3D shape desciptor. The method uses the Gaussian image, which is obtained through mapping of areas and normal vectors for all polygons in an object into the Gaussian sphere. The descriptor is invariant to translation of an object in a scene. The algorithm will be applied to the problem of CBIR (Content Based Image Retrieval). More precisely, the 3D model retrieval is explored.

13

Classifying Visual Objects with the Consistency-Driven Pairwise Comparisons Method

Koczkodaj W. W., Robidoux N., Tadeusiewicz R.

Machine Graphics and Vision

|

2009

|

Vol. 18, No. 2

143-154

EN

The classification of the various image features or visual objects can be carried out by the consistency-driven pairwise comparisons method based on their relative importance. A key issue in the proposed approach is a weight-based synthesis for combining various image features. When compared with the traditional experience-based linear assignment method, the proposed approach is more effective and easy to communicate.

14

Unified JPEG and JPEG-2000 color descriptor for content-based image retrieval

Forczmański P.

Metody Informatyki Stosowanej

|

2008

|

nr 4 (Tom 17)

53--62

EN

The problem investigated in this paper refers to image retrieval based on its compressed form, hence giving much advantages in comparison to traditional methods involving image decompression. The main goal of this paper is to discuss a unified visual descriptor for images stored in the two most popular image formats – JPEG/JFIF and JPEG-2000 in the aspect of content-based image retrieval (CBIR). Since the problem of CBIR takes a special interest nowadays, it is clear that new approaches should be discussed. To achieve such goal a unified descriptor is proposed based on low-level visual features. The algorithm operates in both DCT and DWT compressed domains to build a uniform, format-independent index. It is represented by a three-dimensional color histogram computed in CIE L*a*b* color space. Sample software implementation employs a compact descriptor calculated for each image and stored in a database-like structure. For a particular query image, a comparison in the feature-space is performed, giving information about images' similarity. Finally, images with the highest scores are retrieved and presented to the user. The paper provides an analysis of this approach as well as the initial results of application in the field of CBIR.

15

Metoda wyszukiwania obrazów według ich zawartości wykorzystująca histogramy quasikolorów i dyskretne przekształcenie falkowe

Pisarek M.

Przegląd Elektrotechniczny

|

2007

|

R. 83, nr 5

110-115

PL

W artykule przedstawiono metodę QCH (ang. Quasi-Color Histogram) wyszukiwania obrazów według ich zawartości. Proponowana metoda wykorzystuje globalny znormalizowany histogram quasikoloru, znormalizowane histogramy lokalnych momentów statystycznych quasikoloru oraz znormalizowany histogram jednostek różnicy kierunkowej. Do wyznaczenia globalnego histogramu quasikoloru użyto modelu HSV. Lokalne momenty statystyczne quasikoloru wyznaczane są w przestrzeni RGB, a następnie są konwertowane na wartości w przestrzeni HSV. Do wyznaczenia histogramu jednostek różnicy kierunkowej użyto dyskretnego przekształcenia falkowego (DWT, ang. Discrete Wavelet Transform). W artykule dokonano również porównania proponowanej metody z metodami CLSFH (ang. Color and Local Spatial Feature Histogram) i SCH (ang. Spatial-Chromatic Histogram).

EN

A color image retrieval method using quasicolor histogram, quasicolor statistic moments histogram and directional difference unit histogram is presented in this paper. A global quasicolor histogram is calculated in HSV color space. Local statistic moments are calculated in RGB color space and then they are converted into values of HSV color space. Directional Difference Unit histogram is calculated using Discret Wavelet Transform. Proposed method is compared to CLSFH (Color and Local Spatial Feature Histogram) and SCH (Spatial-Chromatic Histogram) methods.

16

Object extration as a basic process for content-based image retrieval (CBIR) system

Jaworska T.

Opto-Electronics Review

|

2007

|

Vol. 15, No. 4

184-195

EN

This article describes the way in which image is prepared for content-based image retrieval system. Automated image extraction is crucial; especially, if we take into consideration the fact that the feature selection is still a task performed by human domain experts and represents a major stumbling block in the process of creating fully autonomous CBIR systems. Our CBIR system is dedicated to support estate agents. In the database, there are images of houses and bungalows. We put all our efforts into extracting elements from an image and finding their characteristic features in the unsupervised way. Hence, the paper presents segmentation algorithm based on a pixel colour in RGB colour space. Next, it presents the method of object extraction applied to obtain separate objects prepared for the process of introducing them into database and further recognition. Moreover, we present a novel method of texture identification which is based on wavelet transformation. Due to the fact that the majority of texture is geometrical (such as bricks and tiles) we have used the Haar wavelet. After a set of low-level features for all objects is computed, the database is stored with these features.

17

Cumulus cloud synthetic rendering techniques and their evaluations

Maskey M., Newman T. S.

Machine Graphics and Vision

|

2005

|

Vol. 14, No. 4

399-425

EN

Three new techniques for synthesizing realistic renderings of cumulus clouds are introduced and evaluated. The techniques utilize variations of the Perlin Noise and Koch fractals to achieve a reasonable cloud-like shape and texture. To evaluate the quality of renderings produced by the techniques, three classes of texture features are considered using cluster quality measures. Rendering quality is also evaluated versus real images using shape and texture features.