Differ from traditional 3D reconstruction via stereo vision

this paper studies the reconstruction of straight horizontal lines in 3D space from single 2D omni-directional images. It demonstrates that

for symmetric non-central catadioptric systems

the equation of a 3D horizontal line can be estimated using only two points extracted from its image . By exploiting the peculiar property of horizontal line image in catadioptric system

line detection from single omni-directional image can be simplified. Meanwhile

a horizontal line reconstruction algorithm based on main-point image and non-main-point image is developed. Detailed experiments justify that

under the same precision of image point extraction

compared to present primary approaches of reconstruction from four image points

our methods is more straightforward and accurate.