Author Affiliations
School of Electronic and Information Engineering, South China University of Technology, Guangzhou, Guangdong 510641, Chinashow less
Fig. 1. Framework of the proposed algorithm
Fig. 2. Coarse segmentation of ambient light images. (a) Hazy images; (b) histograms of V channel; (c) regional segmentation
Fig. 3. Dynamic ambient light. (a) Hazy images; (b) rough ambient light maps; (c) refined ambient light maps
Fig. 4. Examples of training set. (a) Real hazy images; (b) transmittance images; (c) paired training samples
Fig. 5. Structure of TEN
Fig. 6. Estimation and refinement of transmittance. (a) Hazy images; (b) transmittance estimated by TEN; (c) refined transimittance
Fig. 7. Comparison of transmittance estimation effects. (a) Hazy images; (b) transmittance estimated by TEN2; (c) transmittance estimated by TEN1; (d) restored results of TEN2; (e) restored results of TEN1
Fig. 8. Restored effects of global and dynamic ambient light. (a) Hazy images; (b) results restored by global atmospheric light; (c) results restored by dynamic ambient light
Fig. 9. Dehazing results of different algorithms. (a) Hazy images; (b) method in Ref. [4-5]; (c) method in Ref. [6]; (d) method in Ref. [9]; (e) method in Ref. [10]; (f) proposed algorithm
Training set | Standard deviation | Average gradient | Information entropy | Edge intensity |
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Ref. [6] | 60.21 | 8.22 | 7.21 | 59.26 | Ref. [9] | 59.23 | 8.05 | 7.22 | 58.07 | Ref. [7] | 62.59 | 8.17 | 7.22 | 58.80 | Ref. [18] | 64.02 | 9.55 | 7.21 | 69.03 |
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Table 1. Comparison of average objective indexes of dehazing images using the trained network with different training sets
Algorithm | Standard deviation | Average gradient | Information entropy | Edge intensity |
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Method in Ref. [4-5] | 45.12 | 7.82 | 7.02 | 57.07 | Method in Ref. [6] | 51.35 | 7.65 | 7.14 | 55.50 | Method in Ref. [9] | 51.41 | 7.13 | 7.16 | 51.34 | Method in Ref. [10] | 51.32 | 8.04 | 7.20 | 57.82 | Proposed method | 64.02 | 9.55 | 7.21 | 69.03 |
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Table 2. Comparison of average objective indexes of dehazing images with different algorithms
Image | Algorithm | Standard deviation | Average gradient | Information entropy | Edge intensity |
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Img1 | Method in Ref. [4-5] | 52.95 | 7.47 | 7.40 | 58.53 | Method in Ref. [6] | 61.70 | 7.49 | 7.34 | 59.37 | Method in Ref. [9] | 66.51 | 6.95 | 7.19 | 55.70 | Method in Ref. [10] | 62.45 | 7.27 | 7.34 | 58.09 | Proposed method | 76.28 | 9.00 | 7.54 | 71.62 | Img2 | Method in Ref. [4-5] | 45.33 | 13.02 | 7.47 | 89.47 | Method in Ref. [6] | 49.40 | 11.29 | 7.33 | 76.85 | Method in Ref. [9] | 37.43 | 8.90 | 7.09 | 62.69 | Method in Ref. [10] | 57.02 | 13.05 | 7.53 | 88.99 | Proposed method | 70.11 | 15.25 | 7.63 | 104.10 | Img3 | Method in Ref. [4-5] | 55.74 | 12.98 | 7.41 | 86.35 | Method in Ref. [6] | 55.60 | 12.96 | 7.61 | 86.28 | Method in Ref. [9] | 52.08 | 10.85 | 7.52 | 74.17 | Method in Ref. [10] | 67.54 | 14.61 | 7.62 | 97.78 | Proposed method | 77.63 | 18.01 | 7.23 | 119.85 | Img4 | Method in Ref. [4-5] | 49.30 | 17.69 | 7.54 | 119.87 | Method in Ref. [6] | 49.96 | 15.82 | 7.56 | 107.62 | Method in Ref. [9] | 56.78 | 15.93 | 7.60 | 106.44 | Method in Ref. [10] | 59.89 | 18.47 | 7.75 | 120.96 | Proposed method | 76.47 | 22.08 | 7.60 | 149.85 | Img5 | Method in Ref. [4-5] | 49.67 | 9.81 | 7.27 | 65.23 | Method in Ref. [6] | 49.98 | 10.22 | 7.29 | 67.33 | Method in Ref. [9] | 50.89 | 9.40 | 7.29 | 65.60 | Method in Ref. [10] | 54.45 | 9.89 | 7.24 | 69.11 | Proposed method | 61.95 | 12.11 | 7.36 | 78.80 | Img6 | Method in Ref. [4-5] | 33.07 | 5.11 | 6.82 | 35.96 | Method in Ref. [6] | 51.43 | 5.45 | 7.35 | 38.38 | Method in Ref. [9] | 59.43 | 4.70 | 7.57 | 34.38 | Method in Ref. [10] | 50.14 | 5.03 | 7.40 | 36.77 | Proposed method | 72.29 | 6.75 | 7.63 | 46.94 |
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Table 3. Comparison of objective indicators of dehazing images with different algorithms