Underwater Image Enhancement Based on Multi-Scale Fusion and Global Stretching of Dual-Model

Aimed at the two problems of color deviation and poor visibility of the underwater image, this paper proposes an underwater image enhancement method based on the multi-scale fusion and global stretching of dual-model (MFGS), which does not rely on the underwater optical imaging model. The proposed method consists of three stages: Compared with other color correction algorithms, white-balancing can effectively eliminate the undesirable color deviation caused by medium attenuation, so it is selected to correct the color deviation in the first stage. Then, aimed at the problem of the poor performance of the saliency weight map in the traditional fusion processing, this paper proposed an updated strategy of saliency weight coefficient combining contrast and spatial cues to achieve high-quality fusion. Finally, by analyzing the characteristics of the results of the above steps, it is found that the brightness and clarity need to be further improved. The global stretching of the full channel in the red, green, blue (RGB) model is applied to enhance the color contrast, and the selective stretching of the L channel in the Commission International Eclairage-Lab (CIE-Lab) model is implemented to achieve a better de-hazing effect. Quantitative and qualitative assessments on the underwater image enhancement benchmark dataset (UIEBD) show that the enhanced images of the proposed approach achieve significant and sufficient improvements in color and visibility.

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Underwater Image Enhancement Based on Local Contrast Correction and Multi-Scale Fusion

Journal of Marine Science and Engineering ◽

10.3390/jmse9020225 ◽

2021 ◽

Vol 9 (2) ◽

pp. 225

Author(s):

Farong Gao ◽

Kai Wang ◽

Zhangyi Yang ◽

Yejian Wang ◽

Qizhong Zhang

Keyword(s):

Image Enhancement ◽

Local Contrast ◽

Fusion Method ◽

Formation Model ◽

Low Contrast ◽

White Balance ◽

Multi Scale ◽

Color Distortion ◽

Underwater Image ◽

Enhancement Method

In this study, an underwater image enhancement method based on local contrast correction (LCC) and multi-scale fusion is proposed to resolve low contrast and color distortion of underwater images. First, the original image is compensated using the red channel, and the compensated image is processed with a white balance. Second, LCC and image sharpening are carried out to generate two different image versions. Finally, the local contrast corrected images are fused with sharpened images by the multi-scale fusion method. The results show that the proposed method can be applied to water degradation images in different environments without resorting to an image formation model. It can effectively solve color distortion, low contrast, and unobvious details of underwater images.

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Underwater image enhancement algorithm based on dark channel prior and underwater imaging model

MATEC Web of Conferences ◽

10.1051/matecconf/202133606033 ◽

2021 ◽

Vol 336 ◽

pp. 06033

Author(s):

Zhengping Sun ◽

Fubing Li ◽

Yuying Yang

Keyword(s):

Image Enhancement ◽

Dark Channel Prior ◽

Underwater Imaging ◽

Low Contrast ◽

Underwater Environment ◽

Imaging Model ◽

Underwater Image ◽

Dark Channel ◽

Color Compensation ◽

Enhancement Method

The main reason for the degradation of the underwater image is the light absorption and scattering. The images are captured in the underwater environment often have some problems such as loss of image information, low contrast, and color distortion. In order to solve the above problems, this paper proposes an image enhancement method for the underwater environment. With the help of the underwater imaging model and dark channel prior theory, a new idea of adding transmission correction and color compensation to G and B color channels is proposed. Experimental results show that, compared with the traditional methods, this method has a better effect on the underwater image with less color deviation.

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Underwater Image Enhancement Method Combining color and Luminance

Recent Advances in Electrical & Electronic Engineering (Formerly Recent Patents on Electrical & Electronic Engineering) ◽

10.2174/2352096513999201026225829 ◽

2020 ◽

Vol 13 ◽

Author(s):

ZHAO Baiting ◽

WANG Feng ◽

JIA Xiaofen ◽

GUO Yongcun ◽

WANG Chengjun

Keyword(s):

Image Enhancement ◽

Color Space ◽

Low Frequency ◽

Brightness Enhancement ◽

Color Distortion ◽

Underwater Image ◽

Enhancement Method ◽

Frequency Components ◽

Image Contour ◽

Objective Indicators

Background:: Aiming at the problems of color distortion, low clarity and poor visibility of underwater image caused by complex underwater environment, a wavelet fusion method UIPWF for underwater image enhancement is proposed. Methods:: First of all, an improved NCB color balance method is designed to identify and cut the abnormal pixels, and balance the color of R, G and B channels by affine transformation. Then, the color correction map is converted to CIELab color space, and the L component is equalized with contrast limited adaptive histogram to obtain the brightness enhancement map. Finally, different fusion rules are designed for low-frequency and high-frequency components, the pixel level wavelet fusion of color balance image and brightness enhancement image is realized to improve the edge detail contrast on the basis of protecting the underwater image contour. Results:: The experiments demonstrate that compared with the existing underwater image processing methods, UIPWF is highly effective in the underwater image enhancement task, improves the objective indicators greatly, and produces visually pleasing enhancement images with clear edges and reasonable color information. Conclusion:: The UIPWF method can effectively mitigate the color distortion, improve the clarity and contrast, which is applicable for underwater image enhancement in different environments.

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