Research Of Panoramic Roaming System Based On Fisheye Images

A kind of virtual reality scene roaming technology has been studied in this paper.We use multiple circular fisheye photos as the data source for processing.Installing a fisheye camera at a fixed viewpoint of a scene,we take photos through rotating camera lens in different directions.Generally,we can get four pieces of fisheye image.Some overlapped region exists between every two adjacent image.By processing these images through methods of image region extraction,image correction and image stitching,we can get a panorama image.Using the self-designed panorama browser,we can roam different regions of the scene.In the course of the study of area extraction,we proposed the variable angle line scan method.It is established on the foundation of the traditional line scanning method.By using scan lines of different slope to approach the circular area,the tangent points are detected.We filter these tangent points for fitting a circle.Our method improves the accuracy and flexibility of circular fisheye image area extraction.In the process of correction of distorted images,we proposed longitudinal compression cylindrical surface projection method.We successfully preserve fisheye image near pole information,and overcome the angle limitation of cylindrical surface projection in vertical direction.Experimental results show that our method is better than the latitude and longitude correction method.As for image mosaic,by using similarity threshold selection and symmetric filtering rules,we significantly reduce the number of registration feature points and improve the efficiency of the mosaic.The random sample consensus(RANSAC)strategy is used to improve the accuracy of the estimation of the scene transformation matrix.For the spherical panorama re-projection browsing method,we give a detailed analysis of the process.The implemented browser has basic browsing function,and the browsing scope is around 360 degrees in horizontal and 180 degrees in vertical.It basically reached the practical requirements on the visual senses.