]>Image-Based Framework for Concrete Surface Crack Monitoring and Quantification : Figure 13
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(a)
215295.fig.0013b
(b)
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(c)
Figure 13: Cropped images ( 7 2 × 1 6 0  pixels) of concrete cracks at different times, from (a) to (c), denoted by 𝑇 1 , 𝑇 2 , and 𝑇 3 . By synchronizing with the loading time, 𝑇 1 = 3 0 . 5 seconds, 𝑇 2 = 3 4 . 7 5 seconds, and 𝑇 3 = 3 9 . 7 5 seconds (these time stamps are different from the relative ones used in Figure 10.