A Crack Identification Method for Concrete Structures Using Improved U-Net Convolutional Neural Networks

Table 2

Comparison of the measured crack widths.

Crack number	Measured results	ACTIS measurements	Relative error
1	0.74	0.35	52.7
2	1.10	0.40	63.6
3	0.81	0.41	49.4
4	0.35	0.28	20.0
5	0.33	0.24	27.3
6	0.27	0.24	11.1
7	0.37	0.31	16.2
8	0.43	0.35	18.6
9	0.36	0.27	25.0
10	0.43	0.24	44.2
11	0.36	0.25	30.6
12	0.48	0.30	37.5
13	0.37	0.19	48.6
14	0.42	0.34	19.0
15	0.35	0.23	34.3
16	0.58	0.34	41.4
17	0.37	0.31	16.2
18	0.56	0.39	30.4
19	0.57	0.46	19.3
20	0.45	0.31	31.1