Detection and Positioning of Pipes and Columns with Autonomous Multicopter Drones

Table 2

Detection accuracy and performance of the visual detection of pipe apparent contours.

Contour detection method		Indoor error rate^1	Outdoor error rate^2	Avg. rate
a	Canny + Hough Transform	23.45%	48.71%	8.64 Hz
b	a + Adaptive Binarization	17.29%	33.56%	2.34 Hz
c	LSD + Hough Transform	19.42%	29.38%	21.4 Hz
d	c + LiDAR based priors	1.32%	- ^3	19.78 Hz

positive rate (i.e., a contour not pertaining to the pipe or presenting wrong fitting is found).
outdoors data with LiDAR and image is available.