An Image enhancement algorithm based on Gaussian weighted bilateral filtering and retinex theory

2015 ◽  
Author(s):  
Jian Chang ◽  
Jiahong Bai
Keyword(s):  
Image Enhancement ◽  
Bilateral Filtering ◽  
Retinex Theory ◽  
Enhancement Algorithm

Gaussian Pyramid Transform Retinex Image Enhancement Algorithm Based on Bilateral Filtering

2020 ◽  
Vol 57 (16) ◽  
pp. 161019
Author(s):  
林昌 Lin Chang ◽  
周海峰 Zhou Haifeng ◽  
陈武 Chen Wu
Keyword(s):  
Image Enhancement ◽  
Bilateral Filtering ◽  
Gaussian Pyramid ◽  
Enhancement Algorithm

scholarly journals Improved Bilateral Filtering for a Gaussian Pyramid Structure-Based Image Enhancement Algorithm

Algorithms ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 258 ◽  
Author(s):  
Chang Lin ◽  
Hai-feng Zhou ◽  
Wu Chen
Keyword(s):  
Image Enhancement ◽  
Gaussian Function ◽  
Color Space ◽  
Human Observer ◽  
Bilateral Filtering ◽  
Saturation Intensity ◽  
Gaussian Pyramid ◽  
Retinex Algorithm ◽  
Reflection Component ◽  
Enhancement Algorithm

To address the problem of unclear images affected by occlusion from fog, we propose an improved Retinex image enhancement algorithm based on the Gaussian pyramid transformation. Our algorithm features bilateral filtering as a replacement for the Gaussian function used in the original Retinex algorithm. Operation of the technique is as follows. To begin, we deduced the mathematical model for an improved bilateral filtering function based on the spatial domain kernel function and the pixel difference parameter. The input RGB image was subsequently converted into the Hue Saturation Intensity (HSI) color space, where the reflection component of the intensity channel was extracted to obtain an image whose edges were retained and are not affected by changes in brightness. Following reconversion to the RGB color space, color images of this reflection component were obtained at different resolutions using Gaussian pyramid down-sampling. Each of these images was then processed using the improved Retinex algorithm to improve the contrast of the final image, which was reconstructed using the Laplace algorithm. Results from experiments show that the proposed algorithm can enhance image contrast effectively, and the color of the processed image is in line with what would be perceived by a human observer.

scholarly journals Underwater image enhancement method with non-uniform illumination based on Retinex and ADMM

2021 ◽  
Vol 39 (4) ◽  
pp. 824-830
Author(s):  
Weidong Liu ◽  
Jiyu Li ◽  
Wenbo Zhang ◽  
Le Li
Keyword(s):  
Image Enhancement ◽  
Color Constancy ◽  
Bilateral Filter ◽  
Uniform Illumination ◽  
Illumination Problem ◽  
Underwater Image ◽  
Augmented Lagrange Multiplier ◽  
Enhancement Method ◽  
Retinex Theory ◽  
Enhancement Algorithm

In order to solve the image blurring and distortion problem caused by underwater non-uniform and low illumination, this paper proposes an underwater image enhancement algorithm based on the Retinex theory and the Alternating Direction Method of Multipliers (ADMM). Firstly, the L component of the original image in the Lab space is extracted as the initial illumination map, and an Augmented Lagrange Multiplier (ALM) framework is constructed based on the ADMM to optimize the initial illumination map in order to obtain an accurate illumination image. In addition, the illumination map is further corrected in the luminance region with the Gamma Correction. Secondly, combined with the color constancy characteristics in the Retinex theory, the reflected image of the object is obtained. Finally, the bilateral filter is picked to suppress the underwater noise and obtain a more detailed enhanced image. The experimental results show that the underwater image enhancement algorithm can effectively solve the non-uniform illumination problem caused by natural light or artificial light source and improve the underwater image quality, thus having a better performance than other algorithms.

scholarly journals Grasping Control of a UVMS Based on Fusion Visual Image Enhancement

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Wei Chen ◽  
Lei Wang ◽  
Yuhang Zhang ◽  
Xu Li ◽  
Weiran Wang
Keyword(s):  
Image Enhancement ◽  
Control Method ◽  
Visual Image ◽  
Fusion Image ◽  
Constrained Problems ◽  
Underwater Environment ◽  
Target Ranging ◽  
Retinex Theory ◽  
Resolution Algorithm ◽  
Enhancement Algorithm

The Underwater Vehicle Manipulator System (UVMS) is an essential equipment for underwater operations. However, it is difficult to control due to the constrained problems of weak illumination, multidisturbance, and large inertia in the underwater environment. After the UVMS mathematical model based on water flow disturbance is established, fusion image enhancement algorithm based on Retinex theory is proposed to achieve fine perception of the target. The control method based on redundant resolution algorithm is adopted to establish the anti-interference controller of the manipulator, which can compensate the internal and external uncertain interference. Finally, stable underwater operation is realized. The target ranging method is used to solve the angle of each joint of the manipulator to complete the tracking and grasping of the target. Underwater experiments show that the algorithm can improve the clarity of underwater images, ensure the accuracy of robot capture, and optimize the UVMS control performance.

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