An Improved Flexible Camera Calibration Technique for Rock Three Dimensional Shape Measurement System

Electronic journal of geotechnical engineering

Dahui Qin¹  Haijun Liu¹  Lili Liu¹ 

[1] School of Civil Engineering and Architecture, Southwest Petroleum University, China

关键词: Camera Calibration;    Radial Distortion;    Tangential Distortion;    Maximum Likelihood Estimation;    Rock 3D Shape Measurement;   

DOI  :  

来源: Oklahoma State University

【 摘 要 】

Withtheseadvantagessuchasnophaseshifterror,measuredfast,portable,highaccuracy,thethree-dimensionalmeasurementsystemwhichisbasedontheheterodyneprincipleanddigitalgratingphase-shifttechnologyhasbeenwidelyusedinrockthree-dimensionalshapemeasurement.Theprecisionofcameracalibrationdeterminesthemeasurementaccuracyofthesystem.Inthispaper,theZhangZhengyouplanarflexiblecalibrationmethodisimprovedandanimprovedflexiblecameracalibrationmeansispresented.Thismethodadoptsalensdistortionmodelbasedonsecond-orderradialdistortionandsecond-ordertangentialdistortionandusesahighprecisionplanarcalibrationtargetprintedwithcirculartargets.First,gettingtheinitialvaluesofcameramodelthroughimagepointsnearthecenter,theinitialvaluescanbeagoodapproximationoftheexactvaluesbecausethedistortionofthesepointsnearthecenterissmall.Then,usingtheentirecalibrationboardimages,allparameterscanbeacquiredbyapplyingmaximumlikelihoodestimation.TheexperimentalresultsshowthatthisapproachissuperiortoZhang’sinprecisionandrobustness.

【 授权许可】

Unknown