手机版

Localized Components Analysis(10)

时间:2025-07-10   来源:未知    
字号:

Abstract. We introduce Localized Components Analysis (LoCA) for describing surface shape variation in an ensemble of biomedical objects using a linear subspace of spatially localized shape components. In contrast to earlier methods, LoCA optimizes explicit

LocalizedComponentsAnalysis529

Humeri.3Dsurfacemodelsofhuman,gorilla,andchimpanzeehumerusboneswereobtainedbyscanningthebonesusingalaserrangescanneraspartofalong-termprojectonofprimateevolutionarymorphology.The3Dmodelswereannotatedbyasinglehumanoperator(D.A.)inagraphicalinterfacebyplacingcurvesatanatomicallandmarksontheshaftandproximalanddistalextremitiesofthebone.Acurveontheproximalextremityfollowedthelengthofthearticularneck.Threecurvesweretracedlongitudinallyalongridgesthatspannedthelengthoftheshaft.Onthedistalextremity,curvesfollowedtheridgeoftheolecranonfossa,theridgealongthemediallimitofthetrochlea,theridgealongthelaterallimitofthecapitulum,andtheridgebetweenthetrochleaandcapitulum.Surfacepointssampledfromthesecurvesweretheinputtotheshapeparameterizationmethods.

The rstfewbasisvectorsoftheresultsareshowninFigure5.LoCAidenti edbasisvectorsthatintuitivelydescribedeformationsofthetwojointsurfacesattheextremities,aswellasdeformationsofsub-regionsofthelongbody.

ColobineMonkeyCrania.Theshapespacewasbuiltfromasetof235cra-niafromcolobinemonkeys(SubfamilyColobinae,FamilyCercopithecidae),fromsixAsianspecies.Eachcraniumwasmarkedwith45correspondinglandmarkpoints.Variouscomparativeprimatemorphologistsmanuallymarkedeachcra-niumwith45landmarkpointsusingaMicroscribe3Ddigitizer[19],aspartofdatacollectionforalong-termprojectonOldWorldmonkeycranialevolution.Resultsareshownin gure6.ThelandmarksareshownonaColobusguerezacranium,whichiscoloredasin5.

TheusefulnessofthecompatibilitymatrixBforcreatinglocalizedbaseswithhigher-ordercharacteristicsisalsoillustratedinFigure6.Toencouragespatiallysymmetriccomponents,landmarkpointswerere ectedacrossthemidsagittalplane;patibilityB[i,j]wascomputedbetweenthere ectedpoints,sothattwopointsatcorrespondinglocationsacrossthemidsagittalplane(e.g.,rightandleftcheek)werehighlycompatible.Theresulting“SymmetricLoCA”basisintuitivelycapturesshapevariabilityincorrespondingrightandleftskullfeaturesineachcomponent.

5Discussion

LoCAprovidedasuperiortrade-o ofconcisenessandlocalitythanICAorS-PCAforabroadrangeofdatasets,atacostofgreatercomputationtime.Futureworkwillfocusondesigningcompatibilitymatricesforawiderangeofshapeapplications,usingnon-geodesicdistancemetricsanduser-de nedobjectregionsofinterest.Wewillalsogeneratelocalizedbaseswhosevectorsvarysigni cantlyintheirspatialsuppport;currently,therangeofpossiblespatialsupportsislimitedtoadegreebythedistancemodulatingfunctionf.

…… 此处隐藏:680字,全部文档内容请下载后查看。喜欢就下载吧 ……
Localized Components Analysis(10).doc 将本文的Word文档下载到电脑,方便复制、编辑、收藏和打印
×
二维码
× 游客快捷下载通道(下载后可以自由复制和排版)
VIP包月下载
特价:29 元/月 原价:99元
低至 0.3 元/份 每月下载150
全站内容免费自由复制
VIP包月下载
特价:29 元/月 原价:99元
低至 0.3 元/份 每月下载150
全站内容免费自由复制
注:下载文档有可能出现无法下载或内容有问题,请联系客服协助您处理。
× 常见问题(客服时间:周一到周五 9:30-18:00)