基于最优参数的全景图像三次样条插值复原

全景环形透镜(PAL)将围绕光轴360°的视场投影到环形平面上，具有超大视场，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地展开为常规平面像，解决环形像由外到内压缩引起的分辨率降低的问题。根据PAL成像的特点，以全景图像的最高分辨率为基准，采用三次样条插值，得到插值函数的最佳参数值。此处理结果同最近邻域和双线性插值结果进行比较，较好地恢复了图像细节，同时参数的优化减小图像复原的计算量。

Panoramic image restoration based on optimal parameter cubic spline interpolation

Panoramic annular lens(PAL) project the view of the entire 360° around the optical axis onto an annular plane. Due to the super wide field of view, panoramic imaging system plays important roles in the applications of robot vision, surveillance and virtual reality. An annular image from PAL needs to be unwrapped to conventional rectangular image without distortion. The problem of the decreased resolution from outer circles to inner ones needs to be resolved during unwrapping procedure. The PAL image is restored according to the imaging feature of panoramic annular lens. Referenced to the highest resolution，the image adopts cubic spline interpolation function with the optimal parameter.Compared with nearest and bilinear interpolations ,cubic spline interpolation with optimal parameter can restore the detail of the image better, and decrease the computational cost.