Research On Correction Methods Of Fisheye Image And Video

Fisheye lens is one kind of super-wide lens,fisheye lens has The fish-eye lens has the characteristics of short focal length,large field of view,which could make a single fisheye image contain a large amount of information,and replace a number of traditional lenses.Fisheye lens can work in gaze,without rotating and scanning;while obtaining large field of view at the same time,it has the advantages of small size,better concealment,and saving hardware resources,therefore there is unique application value in fisheye lens.With the continuous innovation of information technology,the extensive application of computer network and the vigorous development of computer vision,fisheye lens has been used in many fields,such as video surveillance,intelligent transportation system,virtual reality technology,robot navigation,medical,panoramic shooting,video group meetings and so on.In the national defense and military,in order to meet theomnidirectional and full time-domain requirement of information acquisition towards the modern war,super-wide lens can also be widely applied.Camera system equipped with super-wide lens can obtain spatial information in omnidirectional and full time-domain way,and utilize the professional information transmission equipment and information processing software,becoming a powerful information access channels in information war.Due to the characteristics of short focal length for the fisheye lens,the images taken have very serious distortion,not only being inconsistent with conventional visual habits of mankind,but also not being used very well.To utilize the large-scale information of these images,rectifying and expanding those distorted images into the perspective projection images that people are accustomed to is necessary.In order to improve the use of fisheye images,the rectification of fish-eye distortion images is one of the key links.(1)Based on the comparison of the imaging principle of the fisheye lens and the pinhole lens and the distortion characteristics of the fisheye lens,an imaging model based on the optical refraction projection was established for the imaging characteristics of the fisheye lens.(2)Combining several classical fisheye image rectification methods,a nonlinear segmented fisheye image rectification method based on optical imaging principle is proposed.Using the optical refraction imaging formula,the fitted polynomial curve is approximated,and the segmentation mapping relation of fisheye image rectification is proposed.The fisheye images are divided into different regions,and rectified with the curves of different parameters respectively,and the circular and full fisheye images can be rectified effectively.(3)The hardware system of driving recorder based on Hi3520 D chip is developed,and the input fisheye image is rectified by using nonlinear segmentation method.The system algorithm is optimized from the aspects of correcting template matrix,data type,calculation process and interpolation algorithm optimization.Eventually,the effect of real-time display is achieved.