序列内窥镜图像的三维结构重建

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1、上海交通大学硕士学位论文序列内窥镜图像的三维结构重建姓名：罗肖申请学位级别：硕士专业：生物医学工程指导教师：秦斌杰20090101摘要列图像进行特征跟踪，并且基于运动一致性约束提出了一种简便的误匹配剔除策略，取得了较好的特征跟踪效果；3．在得到序列图像的匹配特征点对后，利用基于多视图矩阵的迭代分解算法和线性三角形法从运动中恢复出结构，得到了内窥镜当前场景的射影重建结果；4．针对手术过程中可能发生内窥镜摄像机变焦等情形，本文引入了对内窥镜焦距等内参数进行自定标的方法，得到内窥镜的运动轨迹和内窥镜视野的三维欧氏结构，再现了当前内窥镜视野的真实场景。本文对采自上海市第六人

2、民医院的一组鼻腔内窥镜图像进行实验，成功取得了内窥镜摄像机的运动轨迹和鼻腔的三维场景，验证了基于单目内窥镜图像进行三维结构重建方法的可行性。关键词：透视模型，特征点跟踪，SIFT描述子，多视图矩阵，自标定，欧氏重建第II页ABSTRACT3DreconstructionfromendoscopicvideoimagesABSTRACTTheapplicationofendoscopeinminimallyinvasivesurgerywillhelptoguidefuturedevelopmentofsurgery.However,whenusingendoscop

3、etoexaminternalcavitiesinsidethebody,thephysicianscouldonlyseethetwo-dimensional(2D)endoscopicimages,thethree-dimensional(3D)informationinsidethebodyandthereallocationoftheendoscopeareusuallynotavailableunderthemonocularendoscopicsurgery.Inordertosolvetheseproblems,thisthesisintroduces

4、amethodof3Dreconstructionfrommonocularendoscopevideoimages,whichcantrackthetrajectoryoftheendoscopeandreconstructthe3Dscenesoftheinternalcavities.The3Dreconstructionmethodincludesfollowingprocedures:1.Wecalibratetheendoscopeusingnonlinearcameramodelandcorrectthedistortionoftheendoscopi

5、cimages;2.WediscusstheKLTalgorithmintrackingtheendoscopicimagefeaturesandindicatethattheKLTalgorithmwouldfailwhenthescaleand/orthebrightnessoftheimagechangesuddenly.Weproposeanimprovedfeature第III页ABSTRACTtrackingalgorithmwhichuseSIFTdescriptorandfeaturemotionestimationbetweenthetwocons

6、ecutivevideoframes.Wealsoproposeasimpleandconvenientoutlierdetectionstrategybasedonmotionconsistencyconstraints.3.Afterdetectingandmatchingfeaturesintheendoscopicimages,weusethemultiple-viewmatrixbasediterativedecompositionalgorithmandthetriangulationmethodtoreconstruct3Dstructurefromm

7、otion.Fromthis,wegetthe3Dprojectivereconstructionresults.4.Becausethephysiciansmaychangetheendoscopefocusduringthesurgery,weuseendoscopeself-calibrationmethodtocomputerthefocuslengthandupdatethe3Dprojectivereconstructionresultsto3DEuclideanreconstructionresults;Weevaluateourmethodusi