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Utilization of image and signal processing techniques for assessment of built heritage condition
Koudelka_ml., Petr ; Koudelková, Veronika ; Doktor, Tomáš ; Kumpová, Ivana ; Kytýř, Daniel ; Valach, Jaroslav
Historical buildings represent invaluable heritage from the past and therefore their protection is a very important task. Assessment of their condition must not cause damage accumulation thus the least possible volume removed from the structure is essential. As many historical buildings in the Czech Republic are built using sandstone that can be considered as a typical heterogeneous system, statistical signal processing is a promising approach for determination of the representative volume element (RVE) dimensions. Such calculations can be carried out on the domain of logical arrays representing binary images of the materials microstructure. This paper deals with processing of image data obtained using SEM-BSE and high resolution flatbed scanner for determination of RVE dimensions. Advanced image processing techniques are employed and results from calculation using grayscale data are presented and compared with results calculated on the basis of color input images.
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Analysis of Baroque sculpture based on X-ray fluorescence imaging and X-ray\ncomputed tomography data fusion
Vavřík, Daniel ; Kumpová, Ivana ; Vopálenský, Michal ; Lauterkranc, J.
It is advantageous to combine information about geometry and the inner structure of historical artifacts with information about the elemental composition of decorative layers, typically covering historical wooden sculptures. X-ray computed tomography describing artifact structure is quite common and easy. Standard X-ray fluorescence (XRF) analysis of decorative layers is typically done for several selected spots of the artifact’s surface utilizing single pad detector. XRF imaging fully describing the surface’s elemental composition is commonly done for flat objects, while time consuming XRF tomography is applied to relatively small objects. It will be shown in this work that an effective fusion combination of XRF imaging and X-ray tomography describing the whole object can be realized even when using a limited number of XRF images.
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Optimization of acquisition parameters in radiography and tomography
Vopálenský, Michal ; Vavřík, Daniel ; Kumpová, Ivana
Contrast in radiographic images is one of the most important parameters both in radiography and tomography. This paper investigates the possibility of adjusting the radiographic parameters, in particular the accelerating voltage of the X-ray tube, in order to maximize the difference in the detected intensity in response to the change in the thickness of the investigated object. Simplified model is used that allows finding the optimal operating point for the given material and thickness without an apriory knowledge about the X-ray spectra, detector response and the material composition. It is shown that in case of small changes of thickness, the optimum is met when the detected intensity behind the object of certain thickness is at approx. 37 % of the full range (i.e., of the value that would be measured under the same conditions in the absence of the object). In spite of simplifications made, the theoretical model shows a very good correspondence with the experimental data. A brief consideration is made on the case of a general difference in thicknesses.
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Possibilities of using X ray tomography for description of damage of temperature loaded concrete
Rozsypalová, I. ; Kumpová, Ivana ; Daněk, P. ; Šimonová, H. ; Keršner, Z.
The effect of high temperatures on concrete affects the internal structure of this composite material. The paper opens the question of the possibility of using a computed X–ray tomography to quantify the degree of damage of a concrete specimen that was drilled from the selected experimental panel loaded in a fire furnace with high temperatures at the AdMaS (Advanced Materials, Structures and Technologies) research centre at Faculty of Civil Engineering Brno University of Technology. The nominal value of the maximum temperature on the heated side of the panel was 1000 °C. Advanced workstation computer X–ray tomography TORATOM at Centre of Excellence Telč (CET) is parallel imaging of an object in two spectra of X–ray radiation, that allows to highlight differences between the material components to the full X–ray spectrum similar to the attenuation of the radiation.
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Celtic swords
Kumpová, Ivana
The work was focused on the development of the methodology using X-ray tomographic imaging for exploration of metal-based historical artefacts. In the laboratory of X-ray tomography, two objects were examined by this method - two tomography measurements of the early medieval sword in the pre-conservative phase were taken, supplemented by imaging if the bronze bracelet of the same period. The survey was conducted to reveal the technology of production, decoration and possible damage.
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Concrete with steel reinforcement
Kumpová, Ivana ; Jandejsek, Ivan ; Vavřík, Daniel
The work was focused on X-Ray tomography and creating of 3D computer models of ten concrete samples with various steel reinforcement contents and different production technology. From these models, the volume ratios of individual components (concrete: reinforcement: pores) and directional layout of individual fibers were calculated.
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Long bone measurements
Kumpová, Ivana ; Vavřík, Daniel
The work was focused on X-Ray tomography and creating of 3D computer models of historically valuable long bones. Selected slices of reconstructed data in 50% and 35% of each bone length and the entire 3D reconstructions of all specimens, were stored on the supplied medium in DICOM format and forwarded to the client representative together with an extensive measurement protocol.
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