Sensors (Sep 2021)

A New Photographic Reproduction Method Based on Feature Fusion and Virtual Combined Histogram Equalization

  • Yu-Hsiu Lin,
  • Kai-Lung Hua,
  • Yung-Yao Chen,
  • I-Ying Chen,
  • Yun-Chen Tsai

DOI
https://doi.org/10.3390/s21186038
Journal volume & issue
Vol. 21, no. 18
p. 6038

Abstract

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A desirable photographic reproduction method should have the ability to compress high-dynamic-range images to low-dynamic-range displays that faithfully preserve all visual information. However, during the compression process, most reproduction methods face challenges in striking a balance between maintaining global contrast and retaining majority of local details in a real-world scene. To address this problem, this study proposes a new photographic reproduction method that can smoothly take global and local features into account. First, a highlight/shadow region detection scheme is used to obtain prior information to generate a weight map. Second, a mutually hybrid histogram analysis is performed to extract global/local features in parallel. Third, we propose a feature fusion scheme to construct the virtual combined histogram, which is achieved by adaptively fusing global/local features through the use of Gaussian mixtures according to the weight map. Finally, the virtual combined histogram is used to formulate the pixel-wise mapping function. As both global and local features are simultaneously considered, the output image has a natural and visually pleasing appearance. The experimental results demonstrated the effectiveness of the proposed method and the superiority over other seven state-of-the-art methods.

Keywords