简介:Theplenopticcameraisasinglelensstereocamerawhichcanretrievethedirectionoflightrayswhiledetectingtheirintensitydistribution.Inthispaper,torevealmoretruthsofplenopticcameraimaging,wepresentthewavefrontanalysisfortheplenopticcameraimagingfromtheangleofphysicalopticsbutnotfromtheraytracingmodelofgeometricoptics.Specifically,thewavefrontimagingmodelofaplenopticcameraisanalyzedandsimulatedbyscalardiffractiontheoryandthedepthestimationisredescribedbasedonphysicaloptics.Wesimulateasetofrawplenopticimagesofanobjectscene,therebyvalidatingtheanalysisandderivationsandthedifferencebetweentheimaginganalysismethodsbasedongeometricopticsandphysicalopticsarealsoshowninsimulations.
简介:Conventionalcameracalibrationthatemployscalibrationtargetsisacommonlyusedmethodtoacquireacamera'sintrinsicand/orextrinsicparameters.Thecalibrationtargetsareusuallydesignedasperiodicarraysofsimplehigh-contrastpatternsthatprovidehighlyaccurateworldcoordinatesystempointsandthecorrespondingimagepixelcoordinatesystempoints.Theexistingpixelcoordinateextractionalgorithmscanreachasub-pixellevel;however,theytreateachsinglepatterninoneimageasanindependentindividual,whichmakesitdifficulttofurtherimproveextractionaccuracy.Inthispaper,anovelmethodisproposedbyutilizingtheperiodicarrangementcharacteristicsofthecalibrationtargetpatternasaglobalconstrainttoimprovethecalibrationaccuracy.Basedonacamera'spinholemodel,theintersectionpointoftwofittedcurvesisusedasanoptimizedpixelpointtoreplacetheinitialone.Followingthepixelcoordinateoptimizationprocedures,experimentswereperformedusingrealdatafroma3Dlaserlinescannerandadynamicprecisioncalibrationtarget.Ourresultsshowthattherelativeerrorsofcamerahomographymatrixelementsobtainedbytheproposedoptimizationmethodwerereducedcomparedwiththecommonlyusedmethod.Theaveragecoordinatemeasurementaccuracycanbeimprovedbynearly0.05mm.Itisshownthattheproposedoptimizationmethodcanenhancethecameracalibrationaccuracy,especiallywhentheextractedpixelsareofpoorerprecision.
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简介:AIMTo由高分辨率的Placido基于磁盘的地形学把测量的重覆性/重制度与一个高分辨率的旋转Scheimpflug照相机的作比较并且在与keratoconus在眼睛测量角膜的力量估计在二台仪器之间的协议并且在situkeratomileusis(LASIK)激光以后.METHODSOne眼睛每经历了的36个keratoconic病人和20个题目LASIK在这未来的观察研究被包括。二个独立检查人在一份随机的订单工作了与两台仪器拿每只眼睛的三大小。四个参数在前面的角膜上被测量:陡峭的角膜散光计(K),扁平的角膜散光计(Kf),吝啬的角膜散光计(Km),和散光(Ks-Kf)。Intra检查人重覆性和内部检查人的重制度被计算在内题目标准差(Sw)评估重覆性(R),变化(CoV)的系数,和intraclass关联系数(国际计算中心)的系数。在仪器之间的同意被计算.RESULTSInkeratoconic眼睛,intra检查人和内部检查人的国际计算中心是的同意(95%LoA)的95%限制与Bland-Altman方法测试>0.95。作为与由高分辨率的Placido基于磁盘的地形学的测量相比,高分辨率的旋转Scheimpflug照相机的intra检查人R是更低的为Kf(0.32对0.88),K(0.61对0.88),和Km(0.32对0.84)但是为Ks-Kf(0.70对0.57)更高。内部检查人的R值为用高分辨率的旋转Scheimpflug照相机测量的所有参数是更低的。95%LoA是到为Kf,到为K的+0.99的-1.36,到为Km的+0.50的-1.08,和到为Ks-Kf的+1.48的-1.11的+0.55的-1.28。在post-LASIK眼睛,intra检查人和内部检查人的国际计算中心是>0.87为所有参数。intra检查人和内部检查人的R为用高分辨率的旋转Scheimpflug照相机测量的所有参数是更低的。intra检查人R为Kf是0.17对0.88,0.21对0.88为K,0.17对0.86为Km,并且0.28对0.33为Ks-Kf。内部检查人的R为Kf是0.09对0.64,0.15对0.56为K,0.09对0.59为Km�
简介:竞知向学厚德笃行九江学院是经国家教育部批准设立的国有公办全日制本科普通高等院校;向向全国30个省(市、自治区)招生。学校占地2850多亩,校舍面积130余万平方米,全日制在校生3.8万余人。学校还设有1所直辖'三级甲等'附属医院。学校现有专任教师1900余人,其中有副高以上职称的830余人,博士230余人;研究生导师70余人;入选江西省'赣鄱英才555工程'3人;获得国务院特殊津贴和省政
简介:竞知向学厚德笃行九江学院是经国家教育部批准设立的国有公办全日制本科普通高等院校,面向全国30个省(市、自治区)招生。学校占地面积约190万平方米,校舍面积130余万平方米,全日制在校生3.8万余人。学校还设有1所直辖'三级甲等'附属医院。学校现有专任教师1900余人,其中有副高以上职称的830余人,博士230余人;研究生导师70余人;入选江西省'赣鄱英才555工程'3人;获得国务院特殊津