Wyniki wyszukiwania - BazTech

1

Wybrane problemy rozpoznawania obrazów twarzy zarejestrowanych w świetle widzialnym i podczerwieni

Pacan J., Jakubowski J.

Logistyka

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2014

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nr 6

8277--8288

PL

Artykuł dotyczy zagadnienia automatycznego rozpoznawania tożsamości na podstawia obrazów twarzy zarejestrowanych w zakresie światła widzialnego i podczerwieni. Wykorzystywana metoda identyfikacji oparta jest na algorytmie SIFT (ang. Scale Invariant Feature Transform). Łatwość i bezinwazyjność pozyskiwania danych do analizy, jakim jest obraz twarzy badanej osoby, stwarza problemy związane ze zmianami warunków jego akwizycji. W artykule zamieszczono wyniki badań mających na celu ocenę wpływu na proces identyfikacji zmian następujących czynników: natężenia oświetlenia, kierunku padania światła oraz azymutalnego kąta ustawienia urządzenia rejestrującego obraz względem obserwowanego obiektu. Wyniki przeprowadzonych badań wykazują, że zmiany warunków oświetleniowych mają większy wpływ na proces identyfikacji przy analizie obrazów z zakresy światła widzialnego. Wykorzystane w badaniach tradycyjne źródło światła nie wprowadzało znaczących modyfikacji w obrazie z zakresu podczerwieni. Jednak zmiany kąta ustawienia kamery względem twarzy miały negatywny wpływ na proces identyfikacji niezależnie od zakresu spektralnego wykorzystywanych obrazów.

EN

The paper deals with the problem of automatic identification on the basis of face images acquired in visible and infrared spectra. The identification method used in the research is based on the algorithm called SIFT in short (it stands for Scale Invariant Feature Transform). In case of face recognition, acquiring data for the identification process is an easy task and can be done without the cooperation of an examined person or even without their knowledge of being identified. Unfortunately, itcan introduce significant modifications to acquired images because of changing illumination conditions or different positions of the camera in relation to the objectthat is observed. The paper presents the results of the research, which was conducted with the objective of assessing the influence of selected factors, which can modify an acquired image, on the identification process. The results of the research reveal that changes in illumination during image acquisition process have significant influence on the identification process while processing images acquired in visible spectrum. The source of the light used in the research do not introduce visible modifications to infrared images. However, changes in camera position have negative influence on the identification process regardless of the spectrum range of the analyzed images.

2

Mutual influences of sol-gel matrices and dopants on the materials optical properties

Andrzejewski D., Podbielska H.

Optica Applicata

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2001

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Vol. 31, nr 1

223-229

EN

The optical properties of doped sol-gel derived materials were studied. Two types of materials were examined; thin films doped with titanium dioxide and bulks doped with pH indicators: Bromothymol Blue and Nile Red. Different amounts of TiO/sub 2/ (in concentrations: 20, 40, 60 and 80 mol%) were entrapped into the silica sol-gel thin films. The refractive indices of the films were measured. A linear increase of refractive index with increasing addition of TiO/sub 2/ was observed. Bromothymol Blue and Nile Red pH indicators were entrapped into the sol-gel bulks. Two methods of dye immobilization were used. In the first method, indicators were mixed with liquid hydrolyzate used for bulk preparation. In the second one, the dried sol-gel bulks were impregnated with liquid dye solutions. The absorption spectra in the visible range were examined for dyes in solutions and sol-gel bulks. Changes in absorption spectra were observed depending on the way of dopant entrapment.

3

Light attenuation parameters of polydisperse oil-in-water emulsion

Otremba Z., Król T.

Optica Applicata

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2001

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Vol. 31, nr 3

599-609

EN

This paper presents the method and the results of modelling the fight attenuation and absorption spectra in sea water polluted with dispersed oil. The Mie solution has been employed in modelling to derive the cross-sections of light attenuation and its components, absorption and scattering of oil-water emulsion droplets. After the averaging for typical distributions of dispersing particles, these cross-sections allow determination of the optical properties of water polluted with oil substances. It was revealed that oil concentration of about 1 ppm in water causes light attenuation comparable with attenuation in natural water typical for bays of the Baltic Sea (Case 2 waters The method presented facilitates obtaining the information necessary for the modelling of above water upward radiation field in the cases of basins polluted with dispersed oil

4

Device for measurements of selective luminescence excitation spectra of europium (III) based on a nitrogen and dye laser system.

Lis S., Hnatejko Z., Stryła Z.

Optica Applicata

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2001

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Vol. 31, nr 3

643-648

EN

Eu(III) selective excitation spectroscopy involving the /sup 7/F/sub 0/ to /sup 5/D/sub 0/ transition has been briefly characterized as an important luminescence technique for metal binding sites. An experimental system consisting of a nitrogen laser and a tunable dye laser has been modified for measurements of the Eu(III) excitation spectra. The experimental setup gives the possibility for concurrent registration of excitation spectra and luminescence decay curves for every wavelength of excitation. The system is controlled by a PC using a specially written program for collecting and processing the /sup 7/F/sub 0/ to /sup 5/D/sub 0/ spectra of Eu(III).