螺旋锥束工业ct的katsevich精确重建算法分析

《螺旋锥束工业ct的katsevich精确重建算法分析》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、重庆大学硕士学位论文用实际扫描的投影数据进行图像重建，然后对重建的图像进行三维边缘提取。本文对螺旋锥束CT的Katsevich重建公式进行了修改，研究了一种利用螺旋锥束CT获得的投影数据直接重建物体三维增强边缘的方法。通过该方法得到的三维增强边缘，可以初步判断物体内部结构的形状及类型，而且三维增强边缘重建时间与螺旋锥束Katsevich算法重建时间相当，节省了三维边缘提取的时间。关挂词:螺旋锥束工业CT，Katsevich精确重建算法，自适应混合滤波，偏移修正，增强边缘重建英文摘要ABSTRACTCT(ComPutedtom

2、ograPhy)15thefruitbytheeomblnationofmathematies，Physies，Photoeleetricity，meehaniesandeomPuterscience，ete.11eanbeclassifiedintotwomajorPractiealfields:MediealCT(MCT)andIndustrialCT(ICT).DuringthePastfortyyears，theseanmodeofICThasbeendeVelopedintothe3DsPiraleone一beam

3、fromtheZDParailel一beam.SPiralcone一beamICTnow15ahotsPotintheresearehingarea.ItPossessesseveralstrongPoints:notonlyithasshorterscantime，higheraxisresolutionandbetterray’5utilization，butalsoitsseanloeussatisfyneeessaryandsuffieientconditionforthe3Dexactreeonstruetion.

4、ThereeonstruetionalgorithmsofsPiraleone一beameanbedividedintotwosorts:algebraiealgorithmsandanalytiealgorithms.Algebraiealgorithmsneediterationmanytimes，50iteostsmuehtime.TherearetwotyPesofanalytiealgorithms:exactandapProximatealgorithms.ComParedwithapProximatealgor

5、ithms，theimagereeonstruetedfromexactalgorithmsriditselfoftheinflueneeofeoneangle，andhavenoshadowintheasPeetoftheory.Also，therearemaiulytwotyPesofex解talgorithms:GrangeatalgorithmandKatseviehalgorithm.DuetohigherefficieneyofthealgorithmimPlementationandbetterqualityo

6、fthereeonstrUetedimage，thesPiraleone一beamKatsevichexactreeonstruetionalgorithmhasattractedinereasingattention.TheexactreeonstruetionrequiresthattheProjeetionsshouldbeeomPleteandwithoutnoise.Unfortunately，insPiraleone一beamICT，theProjeetionsobtainedfromthePractiealen

7、gineeringhavealotofnoise.Thenoise15eausedbymaladjustmentofsomedeteetors，disPersionandcross一talkofX一rays，ete.hiordertomeettheexactreeonstruetioneondition，thenoisedProjeetionsshouldbede一noisedortheexactreeonstrUetionalgorithmsshouldbeimProved.In而5Paper，twostrategiesw

8、ereadoPtedtoredueethenegativeeffeetsresultedfromthenoisewhentheKatsevichalgorithmwasapPliedtoreconstruetthenoisedsPiraleone一beamProjeetions.Thefi