3d Reconstruction Technology Research And Development Based On 2d Image

3D Reconstruction is one of the main research content of the computer vision technology. In engineering and many other areas, in order to get useful information for research, we usually analyze the 3D structure of the objects. In this paper, 3D reconstruction is based on 2D images, it is a new technology which comes from the combination of the technology of computer vision and computer graphics.The research on 3D reconstruction has important practical significance and has a broad range of applications, such as archeology,architecture,materials processing,industrial inspection,medical imaging equipment industry.At present, there is no effective method to monitor the surface defects of the large casting, researchers always determine defects by naked eyes; this method wastes time and energy, and it is very hard to locate the location of surface defects. To solve these problems, the paper proposes a creative method to defect the surface detection: using the latest technologies of computer vision to detect defects automatically. The principle of this method is: use CMOS camera to obtain the multi-angle images of the surface of large casting; then, process images to get the useful information; finally, the geometric entities of 3D reconstruction and the original geometric entities casting will be contrasted automatically. In this way, we can get the exact location of the surface defects of large-scale casting.Based on the analysis of the camera imaging model and its working principle, the paper gives a plan for space point reconstruction, the paper also studies the conversion relationship between the world coordinate system and pixel coordinate system. Extraction of feature points is the prerequisite conditions and basis of the camera calibration. Before calibration, this paper uses the weighted average to process the image, uses the Harris corner detection method and the Gaussian filter function to get the corner from the image.The paper does not consider the non-linear distortion of the 2D image during the camera calibration. It selects 10 points from the corner points, and obtains the camera projection matrix by means of OpenCV and VC++ programming techniques. Theory analysis and process design are made detailed in paper.Finally, the paper develops a software system on the VC++ platform. It includes reading images, gray-scale processing, corner extraction, camera calibration and reconstruction of the space point. The validity and practicability of studies has been approved by the experiment in the dissertation.