Fisheye image Distortion Correction Based on Spherical Perspective Projection Constraint

Fisheye lens has the prominent advantage of large field of view, which is suitable for the overall environmental monitoring during the restoration of polluted sites. But at the same time, the fisheye lens has a large distortion, which has a great influence on the image matching and stitching between different cameras. Aiming at the shortcomings of traditional wide-angle lens image correction methods, only correction is carried out in the longitude direction, and the correction effect is poor. A fisheye correction algorithm based on spherical perspective projection constraint was proposed, in the case of spherical perspective projection, the space line is no longer projected as a plane line of the image, but as a great circle on the sphere. First, adopt the scan line approximation method to extract the effective area of the fisheye image, to determine the center and radius; then in view of the shortcomings and deficiencies of the spherical coordinate positioning method and the latitude and longitude mapping method. A correction method based on spherical perspective projection constraint is quantized; finally, the experimental verification is carried out. Through the experiment, this method has a good effect on the correction of fisheye image, the shape of the object in the image has been restored, and several arcs have become parallel lines, which are very consistent with the reality.