Studies On 3D Mosaic Technology Of Surface Measurement Based On Stereo Vision

A method of 3D surface mosaic based on a stereo vision measuring system isstudied in this thesis. Reviewed the surface mosaic methods in computer vision, aglobal-coordination-measuring-systems-based three-dimensional surface mosaictechnology is proposed. It overcomes the disadvantage of the most existing methodsof multi-perspective mosaic that having no control on the global error. With thehigh-resolution camera and several control points, a global coordinate system withhigh precision is set up using the camera self-calibration technology. Then, byintroducing the control points of plane form pasted on the measuring object, thetranslation between the global coordinate and the measuring coodinate can be foundout. The 3D data obtained from different viewpoints thus can be translated into aunique frame of refrence. So the final results should be obtained. The main works ofthis thesis are summarized as follows:1. A new 3D surface mosaic method based on the global coordination measuringsystem was introduced. Using the Kodak Professional Digital Camera, The globalcoordinate system was established. Then the 3D data from each stereo visionmeasuring unit can be translated into a unique frame of refrence.2. Designed control points of plane form with homocentric arcs and ball markers.By the moment invariants and least-squared procedure of ellipse fit, the markers wererecognized and located automatically with high precision.3. Studied the technology of camera self-calibration, according to the camerawith wide field of view, set up the distorted projection camera model. Compared withtraditional calibration techniques, self-calibration does not require a calibration objectwith known 3D geometry, but only needs point correspondences from images to solvefor the intrinsic and extrinsic parameters.