Fig. 1. Flowchart of the proposed method

Fig. 2. Color correction results. (a) Raw images; (b) color correction method based on mean and variance; (c) proposed color correction method

Fig. 3. Process of separating and integrating low-enhanced and upper-enhanced regions

Fig. 4. Detail sharpen results. (a) Original image; (b) contrast enhanced image; (c) detail sharpened image

Fig. 5. Evaluation of color correction。(a) Original image; (b) method in Ref.[1]; (c) method in Ref.[5]; (d) method in Ref.[9]; (e) method in Ref.[15]; (f) method in Ref.[16]; (g) method in Ref.[18]; (h) proposed method

Fig. 6. Evaluation on bluish underwater images.(a) Original image; (b) method in Ref.[1]; (c) method in Ref.[5]; (d) method in Ref.[9]; (e) method in Ref.[15]; (f) method in Ref.[16]; (g) method in Ref.[18]; (h) proposed method

Fig. 7. Evaluation on greenish underwater images. (a) Original image; (b) method in Ref.[1]; (c) method in Ref.[5]; (d) method in Ref.[9]; (e) method in Ref.[15]; (f) method in Ref.[16]; (g) method in Ref.[18]; (h) proposed method

Fig. 8. Evaluation on yellowish underwater images. (a) Original image; (b) method in Ref.[1]; (c) method in Ref.[5]; (d) method in Ref.[9]; (e) method in Ref.[15]; (f) method in Ref.[16]; (g) method in Ref.[18]; (h) proposed method

Fig. 9. Evaluation on low light images