Complex Background Removal Method for Video of an Inclined Cable Based on UAV Detection of Structural Vibration Frequencies

Table 8

Frequency differences after the proposed method.

Condition	Method	1-2 (Hz)	2-3 (Hz)	3-4 (Hz)	4-5 (Hz)	5-6 (Hz)	Mean relative error
Short-time condition	Accelerometer	—	0.7109	0.7304	0.7276	0.7276	—
	K-Means	—	0.7372	0.7126	0.7127	0.7126	0.11%
	Region Growing	—	0.7245	0.7245	—	—	0.05%
	RGv2	—	0.7245	0.7245	0.7245	0.7245	0.05%
Long-time condition	Accelerometer	—	0.7110	0.7272	0.7298	0.7272	—
	K-Means	—	0.7119	0.7212	0.7213	0.7212	0.68%
	Region Growing	—	0.7150	0.7181	—	—	1.00%
	RGv2	—	0.7150	0.7181	0.7213	0.7212	0.68%