Distortion correction on gun bore panoramic image

The observing system made up of panoramic annular lens (PAL) can observe objects around the lens, which fits for the quality inspection of gun bore. But there is serious distortion in the tangential and radial directions on the annular image formed through twice reflection. The paraboloid perspective projection model is proposed to correct the image distortion according to the imaging feature of PAL. Firstly, the PAL correction model which includes distortion parameters is constructed. The annular image is transformed back into a cylinder in three-dimensional space under this model. Then spreads out the curved image plane into a flat one. Meanwhile, the distortion parameters are obtained by adopting modified genetic algorithm according to the labelled image. Simulation and panoramic gun bore image experiments demonstrate that this algorithm could greatly correct the tangential and radial distortions and enhance the classified precision of gun bore flaw.