Panoramic Annular Image Interpolation Restoration Based on Edge Detection

In the detection of the feature of the pipeline wall,the observing system made up of PAL can observe objects around the lens without moving parts,and for the special imaging feature of PAL,that can form an annular image.But the annular image formed by PAL is not only unconvenient for observation and measurement,but also has distortion phenomenon.Thus 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,adopt an interpolation method based on edge detection which adopts cubic convolution interpolation for edge and bilinear interpolation for non-edge.Compared with bilinear interpolation and cubic convolution interpolation,this method can restore the detail of the image better and decrease the computational cost.