FLOPs	Floating-Point Operations
mAP	mean Average Precision
VO	Visual Odometry
CCTV	Closed-Circuit Television
IMU	Inertial Measurement Unit
USDID	Urban Sewer Defect Image Database
BN	Batch Normalization
SIFT	Scale-Invariant Feature Transform
PnP	Perspective-n-Point
BA	Bundle Adjustment
SFM	Structure from Motion
MVS	Multiview Stereo
AP	Average Precision
TP	True Positive
FP	False Positive
FN	False Negative