《结构光原理扩展》PPT课件.ppt

三维信息获取与重构技术,实体三维信息获取与重构,Rendering,Shape,Lighting and Reflectance,Motion,Computer Vision,Dept. of Communication Eng.,结构光法背景,C1,一个图像点对应着多个空间点（一条直线无法确定一个点）,双摄像机可确定空间点 （两条直线相交可确定一个点）,立体视觉,Computer Vision,Dept. of Communication Eng.,结构光法背景,C1,立体视觉的关键,两幅图像中对应点的确定,C2,Computer Vision,Dept. of Communication Eng.,结构光法背景,C1,对应点的确定,C2,Computer Vision,Dept. of Communication Eng.,结构光法背景,结构光 系统构成,投影仪代替摄像机 投射特定光源解决对应问题,Computer Vision,Dept. of Communication Eng.,结构光法基本原理,相似三角形 平行直线,推导,结构光系统建模,相似三角形,平行直线,Computer Vision,Dept. of Communication Eng.,结构光法标定,结构光系统标定,相似三角形,平行直线,标定参数： 基线b 摄像机焦距f 投影仪投影角,Computer Vision,Dept. of Communication Eng.,结构光法编码光,光源设计,各种编码方式,Laser Triangulation,Depth from ray-plane triangulation,Object,(x,y),In order to obtain a full range image, what is necessary?,a system must have some methods of determining which stripe is which,Slow, robust,Fast, fragile,Color direct coding,Colored dots Davies 96 A gray wedge Carrihill 85,*Reflectivity assumption Eg. Fails if the surface is textured,Spatial neighborhood,Boyer 87 Proesmans 96,*Spatial coherence（空间相关） assumption Eg. Fails if surface contains discontinuities,0 1,Time-multiplexing,Sato 87,*Temporal coherence（时间相关） assumption Eg. Take several frames to compute depth,Time-multiplexing,Pattern 1,Pattern 2,Pattern 3,随时间投影,该像素的编码值: 1010010 用于识别该点的对应关系,Designing a Code,Project Code,Capture Images,Find Boundaries,Match Boundaries,Decode,Compute Range,Designing a Code,Design a code to make tracking possible: Do not allow two spatially adjacent ghosts Do not allow two temporally adjacent ghosts,t,Graph (for 3 frames):,Edges: boundaries (over time),Designing a Code,Designing a Code,Graph (for 3 frames):,56 edges in graph maximal-length traversal has 64 boundaries (65 stripes),Matching Stripe Boundaries,Project Code,Capture Images,Find Boundaries,Match Boundaries,Decode,Compute Range,Even if number of ghosts is minimized, matching is not easy,?,Calibration,y,x,O,f,P,X(u,v,f),CP(Camera plane),X(x,y,z),L,S(Light plane),PP(Projector plane),X0,z,q,Calibration n,P,Results,projector,CCD,Cup,Results,Video frames,Stripe boundaries,Results,Multiple views by a free-mobile camera,Multiple views by a free-mobile camera,“Wa Wa”,“Athlete ”,Multiple views by a free-