31 May 2022 Diverse image enhancer for complex underexposed image
Ziaur Rahman, Zafar Ali, Inayat Khan, Muhammad Irfan Uddin, Yurong Guan, Zhihua Hu
Author Affiliations +
Abstract

The visual appearance of images changes in line with varying environmental light conditions. Adjusting the exposure of various distorted images is a highly complex process. Previous approaches have addressed this issue from different viewpoints and attained remarkable progress. However, they either failed to achieve visually pleasing results or were suitable for a single class of images (e.g., underexposed or nonuniform images). To fully consider the exposure in various distorted images, we proposed a diverse image enhancement model that improved the brightness and contrast, processed the colors, and eliminated the hazy effect. Accordingly, an input red green blue color image was transformed into a hue, saturation, value color image. The V component was inverted and enhanced using three steps. In the first step, the hyperbolic and statistical methods were applied, and then their results were combined using an adjusted logarithmic methodology. This method properly adjusted the high-contrast and low-contrast impact while preserving the vital image information. In the second step, the output of the first step was inverted back and fed into a complete optimization algorithm to estimate the illumination map. Then, the exposure ratio map was estimated using an illumination map, which was adjusted using the camera response function. In the third step, a nonlinear stretching function was introduced to control brightness and contrast. For instance, a lower value of α yielded maximum stretching, and a higher value of α eliminated haze in the image to a great extent. Finally, an empirical evaluation and comparison of the most recent state-of-the-art approaches on eight datasets revealed that the proposed model efficiently addressed the exposure in various degraded images.

© 2022 SPIE and IS&T 1017-9909/2022/$28.00 © 2022 SPIE and IS&T
Ziaur Rahman, Zafar Ali, Inayat Khan, Muhammad Irfan Uddin, Yurong Guan, and Zhihua Hu "Diverse image enhancer for complex underexposed image," Journal of Electronic Imaging 31(4), 041213 (31 May 2022). https://doi.org/10.1117/1.JEI.31.4.041213
Received: 17 February 2022; Accepted: 12 May 2022; Published: 31 May 2022
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CITATIONS
Cited by 10 scholarly publications.
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KEYWORDS
Image enhancement

Image processing

Visualization

Visual process modeling

Image quality

RGB color model

Performance modeling

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