Study Of Panoramic Stereo Imaging With Single Optical System

Panoramic annular lens system is one of the specific wide angle lenses. After several reflectitons and refractitions, the rays get into the relay lens and image on one sensor. This kind of optical system can project360°field of view onto a cicular image according to the cylinder projecting principle and the size of the system keeps compact. So it has a great application potential in the fields like panorama supervisory and pipe detection.The CCD/COMS sensors can only obtain two-dimensional information. The distance information of the objects in the image is lost in the projecting process. To obtain three-dimensional information, the traditional methods are using two or more lenses or take several pictures in different place to restore the depth information. The traditional binocular vision system is highly developed, but the observation angle of this system is narrow. It cannot obtain the panorama view of object space. So, to satisfy some applications that need360°field of view without any dead angle, people proposed several solutions, but most of them need complicate optical structure or image processing progress.In this paper, a novel real-time stereo system using double co-axial PALs is proposed. The method to extract the depth information is also present. The images of two units are on the same sensor without any overlay, and one circle image is on the other’s blind area. Besides, to eliminate the stray light in the experiment, some special criterions are added into the optimizing process. The simulation and real experiment both prove that the eliminating result is well. The detailed research contents are listed as below:1) The panoramic stereo imaging reaserch background, the technology of wild field of view, the category of the traditional stereo equipments, the present development situation, some typical examples and their advantages and disadvantages are introduced in the first chapter. After that, we put panoramic and stereo together and invent an optical system called panoramic stereo imaging system. This system has a particular imaging principle.2) The relationship of the geometry parameter and the constraint condition is established. After that, we trace the chief ray and obtain the point of intersections on the four surfaces and deduce some universal expressions. We summarize the optimizing methods and propose the evaluating criterion in the panoramic annular lens. Finally, we give some potential application field using this kind of lens.3) The panoramic stereo system’s imaging principle is proposed and the mathematical model is established. Also, we describe the detailed process of how to deign the two panoramic annular lens units, make a prototype and capture the prospective pictures.4) The extracting process of depth information from the picture getting by the above optical system is proposed. We analyze the baseline change caused by the pupil shifting and the solution to this problem. Using the fitting of a polynomial, we can quickly determine the relationship between the baseline’s length and the incident light angles. In the image process, we describe the ways to straighten the picture and match the feature point. In the end, we measure theprecsion of the system’s spatial resolution capability by a prototype and analysis the possible sources of the testing error. 5) A novel stray light evaluation method and some suppression principles of panoramic annular lens system in theory are proposed. By adding stray light suppression optimization function into optical software, a new panoramic annular lens system is designed. The high stray light suppression performance of this system is shown by non-sequential optical simulation software and real experiment compared with a normal panoramic annular lens system which shows its better stray light suppression performance than the normal one.