Author Affiliations
1School of Instrument Science and Opto Electronic Engineering, Beijing Information Science & Technology University, Beijing 100192, China2Institute of Applied Mathematics, Beijing Information Science & Technology University, Beijing 100085, Chinashow less
Fig. 1. Atmospheric scattering model
Fig. 2. Operation flow of mean comparison method of quarter dark channel method and corresponding result. (a) Quarter dark channel method; (b) the same position of original image
Fig. 3. Polarization images captured when polarizer rotates four fixed angles. (a) 0°; (b) 45°; (c) 90°; (d) 135°
Fig. 4. Output images at each stage in mist for scene 1.(a) ; (b) ; (c) dehazing image obtained by single image dark channel method; (d) quarter dark channel process; (e) selection of ; (f) dehazing image
Fig. 5. Dehazing effect in mist for scene 2. (a) Synthetic original hazed image; (b) hazed image obtained by quarter dark channel mean comparison method; (c) hazed image obtained by single image dark channel method; (d)‒(f) local enlarged images of Figs. 5(a)‒5(c)
Fig. 6. Dehazing effect under dense haze for scene 3. (a) Synthetic dense haze image; (b) preliminary defogging effect; (c) dehazing local magnification; (d) corrected dehazing effect; (e) local amplification after correction; (f) single image dark channel dehazing
Fig. 7. Dehazing effect under dense haze for scene 4. (a) Image with haze; (b) dehazing image obtained by proposed method; (c) dehazing image obtained by single image dark channel method; (d)~(f) enlargement images of selected boxes in Figs. 7(a)‒(c)
Fig. 8. Comparison of image gray histograms before and after defogging. (a) Before dehazing of scene 1; (b) after dehazing of scene 1; (c) before dehazing of scene 3; (d) after dehazing of scene 3
Image (mist) | Image with haze | Single image dark channel | Dual images based on quarter dark channel |
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NRSS (scene 1) | 0.10395 | 0.11901 | 0.11809 | NRSS (scene 2) | 0.01445 | 0.05034 | 0.05541 | Mean gradient (scene 1) | 0.0190 | 0.0402 | 0.0517 | Mean gradient (scene 2) | 0.0087 | 0.0141 | 0.0151 |
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Table 1. Effect of dehazing in mist
Image (dense haze) | Image with haze | Single image dark channel | Dual images based on quarter dark channel |
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NRSS (scene 3) | 0.067123 | 0.097424 | 0.099112 | NRSS (scene 4) | 0.24001 | 0.06807 | 0.065991 | Mean gradient (scene 3) | 0.0127 | 0.0395 | 0.0684 | Mean gradient (scene 4) | 0.0066 | 0.0187 | 0.0204 |
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Table 2. Effect of dehazing in dense haze