Research On Measurement Technology Of Dentofacial Model Based On Binocular Stereo Vision

The application of digital measurement technology in the medical field of dental restoration leadsto the simple, accurate, efficient digital process instead of the cumbersome, time-consuming, roughmanual methods, which not only improves the accuracy of the restoration, but greatly reduces thesuffering of patients. Combined with the Practical demands of dental clinic, the technology of Lasermeasurement based on binocular stereo vision has been fully studied in this thesis, such as cameracalibration, laser line center extraction, binocular stereo matching, software&hardware design andimplementation, etc. One laser measurement prototype system for dental model is developed. Thisthesis mainly includes:(1) The two-step calibration method based on iterative optimization is studied and implemented, andthe calibration for two cameras in the measurement system is achieved.(2) A Rapid Recalibration method of measurement system based on a single Plane Target is proposed,which has been validated by experimentation.(3) An improved algorithm for laser line center extraction is proposed. Through the restoring of thepreliminary laser line center, the problems such as destroy of local connectivity and appearance ofdiscrete points are efficiently resolved, and the Accuracy and stability is well improved.(4) A method based on general polar constraint and another one based on polar constraint withProjective rectification are applied respectively to implement the match of the laser line center.Through the comparative experiment it is discovered that the latter is more convenient and effective.(5) The design of some important parameters is obtained by experiments and analysis, and thecorresponding measurement procedures is compiled using VC++2008platform, and a set ofprototype systems of laser measurement based on binocular stereo vision is developed on that basis.Finally, one Measurement example is used to demonstrate the validity of measurement scheme andthe feasibility of correlation algorithm presented in this thesis.