Fig 1.
Flow chart of CrackHHP.
Fig 2.
Divided image into several small grids with the overlapping regions.
Fig 3.
Relationship between crack pixels and LAvg − LMinAvg.
Fig 4.
Experimental results of high-efficiency algorithm.
(a) Original images. (b) Previous pre-extraction images in Ref. [28]. (c) Improved pre-extraction images. (d) Percolation results of the high-efficiency algorithm.
Fig 5.
Experimental results of the high-accuracy algorithm.
(a) Original images. (b) Results of the previous percolation algorithm. (c) Results of the high-accuracy algorithm. (d) Experimental results analysis images (Blue: the accelerated pixels of the previous pre-extraction method; Green: the pixels of the first percolation; Red: the pixels of the second percolation; Black: without being percolated pixels).
Fig 6.
Experimental results of combination algorithm.
(a) Percolation results of the combination algorithm. (b) Experimental results analysis images (Blue: the accelerated pixels of improved pre-extraction method; Green: the pixels of the first percolation; Red: the pixels of the second percolation; Black: without being percolated pixels).
Fig 7.
Experimental results with different algorithm.
(a)original images. (b)ground truth. (c)the improved pre-extraction images. (d)previous percolation algorithm. (e) CrackForest. (f) CrackHHP.
Fig 8.
Precision rate comparison.
Fig 9.
Recall rate comparison.
Fig 10.
Results of different algorithms on CFD (from left to right: Original image, ground truth, FFA, CrackTree, CrackForest, CrackHHP).
Fig 11.
Precision rate comparison.
Fig 12.
Recall rate comparison.
Table 1.
The time-consuming comparison.
Table 2.
The efficiency analysis of CrackHHP.