Chinese Journal of Liquid Crystals and Displays, Volume. 37, Issue 12, 1580(2022)

Non-uniform illumination image enhancement via symmetric brightness mapping and virtual multi-exposure fusion

Zi-meng HUANG1, Wang-ming XU1,2、*, and Yuan DAN1
Author Affiliations
  • 1School of Information Science and Engineering,Wuhan University of Science and Technology,Wuhan 430081,China
  • 2Engineering Research Center for Metallurgical Automation and Detecting Technology of Ministry of Education,Wuhan University of Science and Technology,Wuhan 430081,China
  • show less

    Aiming at the problems of low contrast, unclear details and poor visualization in non-uniform illumination images due to over-dark or over-bright local regions, an image enhancement method via symmetric brightness mapping and virtual multi-exposure fusion is proposed. A color space conversion is used to retain the hue and saturation components and separate the brightness component of the input image for enhancement processing. According to the camera response model, the principle of image information entropy and average gradient maximization is adopted to estimate the optimal exposure ratio. A pair of symmetrical brightness mapping functions are designed to generate virtually corresponding images with the enhanced exposure and reduced exposure, forming an image sequence with different exposures together with the original brightness component. Then, a multi-exposure fusion method with detail enhancement is applied to the image sequence to reconstruct the enhanced result. Experimental results indicate that the average values of evaluation indices such as image information entropy, average gradient, image contrast, and color consistency of the proposed method are 7.644, 9.209, 450.683 and 0.962 on seven public datasets respectively, which are superior to those of the contrast method and achieve enhanced results with high dynamic range, strong contrast, clear details and good visualization.

    Tools

    Get Citation

    Copy Citation Text

    Zi-meng HUANG, Wang-ming XU, Yuan DAN. Non-uniform illumination image enhancement via symmetric brightness mapping and virtual multi-exposure fusion[J]. Chinese Journal of Liquid Crystals and Displays, 2022, 37(12): 1580

    Download Citation

    EndNote(RIS)BibTexPlain Text
    Save article for my favorites
    Paper Information

    Category: Research Articles

    Received: May. 18, 2022

    Accepted: --

    Published Online: Nov. 30, 2022

    The Author Email: Wang-ming XU (xuwangming@wust.edu.cn)

    DOI:10.37188/CJLCD.2022-0172

    Topics