Panoramic image restoration based on optimal parameter cubic spline interpolation

Abstract

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.