Fig 1.
Demonstration of (a) Earphone image and (b) Otsu binarization result.
Some methods cannot correctly identify binary images with unevenly illuminated backgrounds.
Fig 2.
The square rectangles with blue font are the calculation processes, and the round rectangles with white font represent the calculation results.
Fig 3.
Gaussian function surface with different σs.
(a) σ = 1.5, and (b) σ = 3.
Fig 4.
Establishment of the GSS.
Fig 5.
Estimated target image.
Fig 6.
Result of γ correction.
Fig 7.
Brighter images (a)~(d) and corresponding masks (e)~(h).
The brightness of images (a)~(d) is higher, and the targets are clear. In addition, images (e)~(h) are the result of manual segmentation corresponding to (a)~(d).
Fig 8.
Darker images (a)~(d) and corresponding masks (e)~(h).
The brightness of images (a)~(d) is lower, and the targets are slightly blurred. In addition, images (e)~(h) are the result of manual segmentation corresponding to (a)~(d).
Fig 9.
Scatter distribution of the running time.
Fig 10.
Average (a) ME curve and (b) MIOU, PA, F_Measure curves.
Fig 11.
Scatter distributions of the (a) MIOU, (b) PA, (c) F_Measure, and (d) ME.
Fig 12.
The results of Fig 7a binarized by several methods.
(a) water flow method, (b) SSP method, (c) Wang’s method, (d) Otsu method, (e) k-means method, and (f) proposed method. Some flaws of the comparison methods are shown in red frames.
Fig 13.
The results of Fig 8a binarized by several methods.
(a) water flow method, (b) SSP method, (c) Wang’s method, (d) Otsu method, (e) k-means method, and (f) proposed method. Some flaws of the comparison methods are shown in red frames.
Fig 14.
The results of some text images.
(a) water flow method, (b) SSP method, (c) Wang’s method, (d) Otsu method, (e) k-means method, and (f) proposed method.
Fig 15.
The results of some text images.
(a) water flow method, (b) SSP method, (c) Wang’s method, (d) Otsu method, (e) k-means method, (e) PFE method and (g) proposed method.
Table 1.
Quantitative performance of the six comparison methods and our method.
Table 2.
Quantitative performance of Long’s method and ours.
Fig 16.
Demonstration of our method (a)~(d) and Long’s method (e)~(h).
Fig 17.
Nontext images (a)~(d) and their corresponding masks (e)~(h).
Fig 18.
Scatter distribution of running times.
Fig 19.
Average (a) ME curve and (b) MIOU, PA, and F_Measure curves.
Fig 20.
Scatter distributions of (a) MIOU, (b) PA, (c) F_Measure, and (d) ME.
Fig 21.
The results of Fig 17a.
(a) water flow method, (b) SSP method, and (c) Wang’s method. Some flaws of the comparison methods are shown in red frames.
Fig 22.
The results of Fig 17a.
(a) Otsu’s method, (b) k-means method, (c) PFE method, and (d) proposed method. Some flaws of the comparison methods are shown in red frames.
Fig 23.
The results of some nontext images.
(a) water flow method, (b) SSP method, and (c) Wang’s method.
Fig 24.
The results of some nontext images.
(a) Otsu’s method, (b) k-means method, (c) PFE method, and (d) proposed method.
Table 3.
Quantitative performance of the six comparison methods and our method.
Fig 25.
Demonstration of our method (a)~(c) and Longs’ method (d)~(f).
Table 4.
Quantitative performance of Long’s method and our method.