再用一种简单的数学模型即球面投影，实现了180度鱼眼图像的还原。

Then we transform the fisheye image of 180 degree to normal perspective image.

极面全景画（Polar panoramas），也称为球面投影或“小行星”，是由全景照片创造出来的叹为观止的图片。

Polar panoramas, also known as stereographic projections or 'little planets', are spectacular images that are created out of panoramic photos.