Suppression of residual gradients in the flat-field corrected images

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378297%3A_____%2F19%3A00507997" target="_blank" >RIV/68378297:_____/19:00507997 - isvavai.cz</a>

Výsledek na webu

<a href="http://www.ndt.net/?id=23716" target="_blank" >http://www.ndt.net/?id=23716</a>

DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Suppression of residual gradients in the flat-field corrected images

Popis výsledku v původním jazyce

Flat field correction, based on using the open beam and the dark field images, is a basic method used for correction of the projection images acquired in computed tomography process. The correction suppresses the stationary noise of the detector, caused by non-uniform gain and offset of each pixel, as well as the non-uniformity of intensity caused by the non-flat intensity profile of the incident X-rays beam. In an ideal case, the corrected image should have a constant intensity in the open-beam areas, i.e., everywhere outside the investigated object. However, this is not always true due to several factors, such as drifts of the spot position, wearing out of the target (pitting), etc. In such a case, the background in the flat-field corrected image is not really “flat” or constant. Particularly in radiography, this is an undesired effect, because the intensity values are also influenced in the object area, leading thus to a possible misinterpretation of the image (even for a constant thickness area, the intensity distribution looks like if the thickness was varying). In this paper, a method is described how to compensate this effect in rather an effective way.

Název v anglickém jazyce

Suppression of residual gradients in the flat-field corrected images

Popis výsledku anglicky

Flat field correction, based on using the open beam and the dark field images, is a basic method used for correction of the projection images acquired in computed tomography process. The correction suppresses the stationary noise of the detector, caused by non-uniform gain and offset of each pixel, as well as the non-uniformity of intensity caused by the non-flat intensity profile of the incident X-rays beam. In an ideal case, the corrected image should have a constant intensity in the open-beam areas, i.e., everywhere outside the investigated object. However, this is not always true due to several factors, such as drifts of the spot position, wearing out of the target (pitting), etc. In such a case, the background in the flat-field corrected image is not really “flat” or constant. Particularly in radiography, this is an undesired effect, because the intensity values are also influenced in the object area, leading thus to a possible misinterpretation of the image (even for a constant thickness area, the intensity distribution looks like if the thickness was varying). In this paper, a method is described how to compensate this effect in rather an effective way.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

10201 - Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8)

Projekt

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Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

9th Conference on Industrial Computed Tomography (iCT) 2019

ISBN

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ISSN

1435-4934

e-ISSN

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Počet stran výsledku

5

Strana od-do

23716

Název nakladatele

NDT.net

Místo vydání

Bad Breisig

Místo konání akce

Padova

Datum konání akce

13. 2. 2019

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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