scholarly journals Color image enhancement based on nonlinear filter and retinex algorithm

2017 ◽  
Author(s):  
Hazim G. Daway ◽  
Firas S.A. Ameer ◽  
Hana' H. kareem
Keyword(s):  
Image Enhancement ◽  
Color Image ◽  
Nonlinear Filter ◽  
Color Image Enhancement ◽  
Retinex Algorithm

scholarly journals Low and non-uniform illumination color image enhancement using weighted guided image filtering

2021 ◽  
Author(s):  
Qi Mu ◽  
Xinyue Wang ◽  
Yanyan Wei ◽  
Zhanli Li
Keyword(s):  
Image Enhancement ◽  
Color Image ◽  
Image Filtering ◽  
Uniform Illumination ◽  
Color Distortion ◽  
Color Image Enhancement ◽  
Restoration Algorithm ◽  
Retinex Algorithm ◽  
Color Restoration ◽  
Guided Image Filtering

AbstractIn the state of the art, grayscale image enhancement algorithms are typically adopted for enhancement of RGB color images captured with low or non-uniform illumination. As these methods are applied to each RGB channel independently, imbalanced inter-channel enhancements (color distortion) can often be observed in the resulting images. On the other hand, images with non-uniform illumination enhanced by the retinex algorithm are prone to artifacts such as local blurring, halos, and over-enhancement. To address these problems, an improved RGB color image enhancement method is proposed for images captured under non-uniform illumination or in poor visibility, based on weighted guided image filtering (WGIF). Unlike the conventional retinex algorithm and its variants, WGIF uses a surround function instead of a Gaussian filter to estimate the illumination component; it avoids local blurring and halo artifacts due to its anisotropy and adaptive local regularization. To limit color distortion, RGB images are first converted to HSI (hue, saturation, intensity) color space, where only the intensity channel is enhanced, before being converted back to RGB space by a linear color restoration algorithm. Experimental results show that the proposed method is effective for both RGB color and grayscale images captured under low exposure and non-uniform illumination, with better visual quality and objective evaluation scores than from comparator algorithms. It is also efficient due to use of a linear color restoration algorithm.

A Retinex algorithm for night color image enhancement by MRF

2014 ◽  
Vol 22 (4) ◽  
pp. 1048-1055 ◽  
Author(s):  
赵宏宇 ZHAO Hong-yu ◽  
肖创柏 XIAO Chuang-bai ◽  
禹晶 YU Jing ◽  
白鹭 BAI Lu
Keyword(s):  
Image Enhancement ◽  
Color Image ◽  
Color Image Enhancement ◽  
Retinex Algorithm
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