Fig. 1. Diagram of the optical degradation model.

Fig. 2. (a) Flow chart of the construction of M; (b) flow chart of the calculation of Iu.

Fig. 3. Flow chart of the exposure fusion.

Fig. 4. Calculating four saturation threshold values of an HDR dehazed image.

Fig. 5. Generating a bracketed exposure sequence and fusing them into an SDR dehazed image.

Fig. 6. Flow chart of the proposed polarimetric dehazing algorithm.

Fig. 7. Hazy images and corresponding dehazed results.

Fig. 8. (a) Sky area of images of the experimental group (c); (b) pylon in images of the experimental group (a); (c) pylon in images of the experimental group (e).

Fig. 9. (a) Hazy image; (b) estimated DoLP by the low-rank approximation method; (c) estimated DoLP by the Stokes method; (d) dehazed image based on DoLP shown in (b); (e) dehazed image based on DoLP shown in (c); (f)–(i) local views corresponding to (b)–(e), respectively.

Fig. 10. (a) Estimated intensity map of scattering light based on estimated DoLP by low-rank approximation method; (b) estimated intensity map of scattering light based on estimated DoLP by the Stokes method; (c), (d) local views corresponding to (a), (b), respectively; (e) intensity curves of pixels on the line of y=400 in (a) and (b).

Fig. 11. (a) Hazy image; (b) HDR dehazed image; (c) SDR dehazed image by the MVEF; (d)–(g) SDR dehazed images by the gamma correction with different values of γ.

Fig. 12. Standard variances of images shown in Fig. 11.

Fig. 13. Hazy images and corresponding dehazed images by the proposed method and our previous method [17].

Fig. 14. (a) Hazy image; (b) denoised intensity map of scattering light by the low-rank approximation method; (c) denoised intensity map of scattering light by the low-pass filtering method; (d) dehazed image based on DoLP shown in (b); (e) dehazed image based on DoLP shown in (c); (f), (g) local views corresponding to (d) and (e), respectively.

Fig. 15. Local areas in hazy images and corresponding dehazed images shown in Fig. 13.