Research Of 3-d Reconstruction Based On Colorful Stripe Structured Light

Three-dimensional reconstruction is the main purpose of machine vision and key issue in computer-aided design. Among the various modeling and reconstruction technologies, structured light is being widely used because of its advantages such as simplicity, no touch, wide detection range and high accuracy.The research of three-dimensional reconstruction based on colorful stripe structured light is addressed in this thesis. The main work of the thesis includes coding and decoding strategy of the colorful stripe, color identification strategy, edge detection method, camera and projector calibration, three-dimensional position calculation and reconstruction.Firstly, a coding strategy for colorful stripe is proposed in the thesis. To meet the uniqueness requirement of code word, which can simplify the decoding process, a new type of projection pattern based on the colors of the eight corners on the RGB cube is proposed in the thesis. In order to detect the complete and accurate edges in the colorful image, an edge detection method is proposed which firstly extracts the edges in R, G, B channels separately and then combines these three results together. The credibility of this edge detection method has been shown by the experimental results.Secondly, in order to minimize the interference effect of lightness, the color data is transformed from RGB space to HSI space. A color identification algorithm combining channel threshold and HSI space is proposed, which identifies black and white colors by threshold and the other six colors in HSI space to accomplish the color identification of the eight colors used in coding. A decoding strategy using the stripe color is addressed to overcome the discontinuity problem. The results indicate that the proposed methods are effective.Thirdly, in the calibration process the world and image coordinates of the marks' centers on the calibration plate are applied to optimize the camera projection matrix. The calibration of the projector is accomplished on the basis of camera projection matrix and plane equation of the calibration plate.Lastly, the three-dimensional position calculation is carried out by using the parameters of the camera and the projector. The three-dimensional reconstruction is implemented based on spline interpolation. The effectiveness and advantages of the proposed method in the thesis are proved by the experimental results.