全景环形透镜(PAL)是基于平面圆柱投影法将围绕光轴360°的视场投影到环形平面上,具有景深无限远,图像映射关系为线性特点,在机器人视觉、监控和虚拟现实领域有着重要的应用。实际应用中需要将环形像无失真的展开为常规平面像,此过程需要进行插值处理,三次样条插值精度较高,但是速度很慢。文章采用Bezier曲面的插值算法,并针对全景图像的特点,提出了Bezier曲面的全景图像快速插值算法,使得图像分辨率比样条插值和双线性插值得到改善的同时,插值处理时间比三次样条插值缩短了80%左右。

Panoramic Annular Lens (PAL) project the view of the entire 360 degrees around the optical axis onto an annular plane based on the method of flat cylinder projection.Due to the infinite depth of field and the linear mapped relationship between an object and an image,panoramic imaging system plays important roles in the applications of robot vision,surveillance and virtual reality.An annular image needs unwrapping to conventional rectangular image without distortion,in which interpolation is necessary.Although cubic B-splines interpolation can enhance the resolution of unwrapped image,it occupies too much time to be applied in practice.Considering the characteristic of panoramic image,a swift interpolation algorithm based on Bezier surface is proposed.Compared with cubic B-splines and bilinear interpolation image,the result indicates that the resolution of the image is well enhanced.Meanwhile,the time consumed is shortened by 80% in comparison with cubic interpolation.