基于雙能CT系統(tǒng)的物質(zhì)密度識別算法研究.pdf

1、中國科學(xué)技術(shù)大學(xué)碩士學(xué)位論文基于雙能CT系統(tǒng)的物質(zhì)密度識別算法研究姓名：王輝申請學(xué)位級別：碩士專業(yè)：模式識別與智能系統(tǒng)指導(dǎo)教師：康南生20100501AbstractAbstractX—raydeviceisasignificanttechniquetoidentifysubstance，whichhasdemonstratedtheabilitytocharacterizeamaterialatthemolecularandatomi

2、clevelIthasbeenpenetratedintomulti—disciplines，such：asbranchesofDetectionTechnologyElectronisTechnologyComputersandSOonNowithasbeenwidelyappliedtoindustryagricultureandbiomedicalThisabilityisalsoparticularlyimportantford

3、etectingillicitmaterialswhichhasbeenprovedaneffectivesecurityinspectionmethodandhasbeenappliedinpublictrafficstationsbutthecurrentinspectionsystemcanonlydetectmetalsubstances，thedrugandexplosives，moredangerousmaterialCan

4、notbedetectedTherefore，thesupportprojectofthispaperis，Throughin—depthstudyinthereconstructionmethodsofhigh—speedX—raythepaperwantstoproposenewideasofdetectingdrugandexplosion，andtomakesomecontributionforthedevelopmentofs

5、ecuritycheckofchinaAsthetraditionalmonochromaticXraydetectionmethodscanonlyseethebasicshapesoftheobjectfromtheimageoftheprojection，Butcan’tidentifythematerialcompositionordensityhoweVer，thedensityisoneofthebasesdistingui

6、shbetweendifferentsubstances，SOthedensityidentifyplaysaveryimportantroleindrugsandexplosivesdetectionfieldDuetOthecurrentCTimagereconstructionalgorithmsarebasedonthepremiseofmonochromaticX—raybeambuttheactualuseoftheXray

7、beamispolychromatic，SOthehardeningeffectwillproduce，thereforeitisnecessarytoeliminatetheimpactofbeemhardeningeffectForapolychromaticspectrumxrayCTsystem，weputforwardarecognitionalgorithmofmaterialdensitybasedondualenergy

8、curve，F(xiàn)irstlyCalibrationofthematerialdualenergycurvethroughtheprojectionvaluewithhighandlowdualenergyoftheimagewegot，SecondlyReversesearchtOdeterminethethicknessofthematerialhasbeendetectedLastlyThefilteredback—projectio

9、nreconstructionalgorithmforreconstructingtheelectrondensitydistributionofthematerial，thisrecognitionalgorithmcannotonlyeliminatingthebeamhardeningeffects，butalsowithhighprecisionofthematerialdensity，Combinedwithskyscanl0