Wyniki wyszukiwania - BazTech

1

Fast Granulometry Operator for the 3D Identification of Cell Structures

Brun E., Ferrero C., Vicente J.

Fundamenta Informaticae

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2017

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Vol. 155, nr 4

363--372

EN

The granulometry operator is a mathematical operator largely employed in the 3D analysis of porous media to estimate the sizes of the pores detected in pervious materials and tissues. Quantifying the total porosity volume in a material with only closed pores is a relatively easy task. A simple numerical analysis of connected void or fluid phase components enables one to obtain such a volume. Unfortunately, for materials and/or tissues with (partly) open porosity granulometry calculations might become excessively time and memory consuming. In this work we suggest a method by means of which the open porosity map can be rapidly calculated on the basis of a pre-calculated distance map.

2

A New Idea of Fast Three-Dimensional Median Filtering for Despeckling of Optical Coherence Tomography Images

Gocławski J., Sekulska-Nalewajko J.

Image Processing & Communications

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2015

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Vol. 20, no. 3

25--34

EN

Median filtering has been widely used in image processing for noise removal because it can significantly reduce the power of noise while limiting edge blurring. This filtering is still a challenging task in the case of three-dimensional images containing up to a billion of voxels, especially for large size filtering windows. The authors encountered the problem when applying median filter to speckle noise reduction in optical coherence tomography images acquired by the Spark OCT systems. In the paper a new approach to the GPU (Graphics Processing Unit) based median smoothing has been proposed, which uses two-step evaluation of local intensity histograms stored in the shared memory of a graphic device. The solution is able to output about 50 million voxels per second while processing the neighbourhood of 125 voxels by Quadro K6000 graphic card configured on the Kepler architecture.

3

3D Segmentation of Funnel Flow Boundary During Silo Emptying

Waktola S., Babout L., Grudzien K.

Image Processing & Communications

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2014

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Vol. 19, no. 2-3

141--149

EN

The paper presents an automatic method for segmenting 3D tomography images of a funnel flow area, during silo emptying process. For generating 3D images the silo model was scanned using X-ray Computed Tomography (CT) system. The method has been applied for a chosen single slice from 3D image. The image segmentation is based on the variance of pixels calculation in defined interrogation window (or kernel). The analysis of Signalto- Noise-Ratio (SNR) of the given image allows to improve the contrast in the image and facilitate the detection the boundary between funnel area and stagnant zone. The obtained results of image segmentation show a high potential in the silo flow investigation using in-situ experiment using X-ray visualization. Additionally, the study indicates that, the separation of the silo area into the funnel and stagnant zone parts is a very challenging task especially for the top and bottom area of silo where the contrast is the smallest.

4

Fast 3D Segmentation of Hepatic Images Combining Region and Boundary Criteria

Reska D., Boldak C, Kretowski M

Image Processing & Communications

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2012

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Vol. 17, no. 4

31--38

EN

A new approach to the liver segmentation from 3D images is presented and compared to the existing methods in terms of quality and speed of segmentation. The proposed technique is based on 3D deformable model (active surface) combining boundary and region information. The segmentation quality is comparable to the existing methods but the proposed technique is significantly faster. The experimental evaluation was performed on clinical datasets (both MRI and CT), representing typical as well as more challenging to segment liver shapes.

5

Zamykanie topologicznych i wolumetrycznych otworów w obiektach 3D

Janaszewski M., Postolski M., Babout L., Jopek Ł.

Automatyka / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie

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2011

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T. 15, z. 3

131-141

PL

Zamykanie otworów w obiektach reprezentowanych na trójwymiarowych obrazach wokselowych jest istotnym problemem mającym zastosowanie w analizie medycznych obrazów tomograficznych, a także obrazów materiałów. Niniejszy artykuł prezentuje nowy algorytm zamykania otworów zarówno geometrycznych, jak i topologicznych. Zgodnie z wiedzą autorów jest to pierwszy algorytm, który umożliwia zamykanie obu typów otworów w obiektach reprezentowanych na obrazach binarnych 3D.

EN

Hole closing in 3D volumetric objects is an important problem in tomography image analysis applied in medicine and material science. The article presents new algorithm for geometric and topological hole closing. According to the authors knowledge the presented algorithm is the first which closes both types of holes in 3D volumetric objects.

6

Nowe techniki rekonstrukcji trójwymiarowych obrazów i kształtów dla tomografii pojemnościowej

Banasiak R., Wajman R.

Zeszyty Naukowe. Elektryka / Politechnika Łódzka

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2010

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z. 121

89-106

PL

W poniższym artykule przedstawiono podstawowe wyniki badań nad rozwojem nowych metod rekonstrukcji obrazu dla trójwymiarowej elektrycznej tomografii pojemnościowej. W ramach tych badań został opracowany szereg nowych algorytmów, między innymi: algorytm wyznaczający rozkład czułości sensora w węzłach siatki metody elementów skończonych oraz algorytmy nieliniowej rekonstrukcji obrazów oraz kształtów z uwzględnieniem kompletnego modelu numerycznego trójwymiarowej sensora pojemnościowego. Ponadto w artykule zaprezentowano przykładowe rekonstruowane obrazy uzyskane przy pomocy opracowanych algorytmów.

EN

This paper presents some results of the research on new reconstruction techniques for 3D electrical capacitance tomography development. This works covers new algorithms e.g. new nodal jacobian matrix calculation and nonlinear image and shape reconstruction techniques using new complete 3D capacitance sensor computational model. Furthermore few examples of reconstructed 3-dimensional images are presentes using described methods.

7

Models for 3D vascular image analysis

Orkisz M., Hernández Hoyos M.

Journal of Medical Informatics & Technologies

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2001

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Vol. 2, Part. 1

IP13--IP22

EN

In image processing, models are used to improve robustness of algorithms by introducing a priori knowledge. Deformable models, frequently used in the field of medical images, are described by means of energy functionals with data attachment terms and regularising terms. The regularising terms express constraints relating to the expected shapes. The expected shape of a blood vessel segment in 3D images obtained by Magnetic Resonance Imaging or by helicoidal Computed Tomography is often implicitly described by a generalised cylinder model, i.e. an association of an axis (vessel centreline) and a surface (vessel boundary). In this context, the data attachment terms involve, for candidate points, a measure of the likelihood of being located on the centreline or on the boundary. Such a measure can use models reflecting low-level local photometrical properties of the brightness patterns. This presentation will give an overview of the recently used models and will be illustrated by the authors' contribution.