Raw data acquired by imaging devices are converted into digital images by post-processing algorithms. However, these algorithms are significantly affected by numerous illumination conditions. Particularly, in the case in which illumination conditions depend on canonical light sources, unwanted light sources that locally illuminate the scene or mixed light from several light sources are recognized as the spatially varying illumination conditions. These complex illumination conditions cause several artifacts by affecting the digital image acquisition process. For example, optical aberrations are generated by refraction of complex light, or illumination estimation is significantly affected by the different color temperatures of multiple light sources. To overcome these problems, this study proposes an algorithm that decomposes the complex illumination from several light sources. First, the spatially varying illumination condition is discussed, and the artifacts generated by the conditions, such as false colors and aberrations, are analyzed. Second, mixed light from several canonical light sources is decomposed based on the imaging devices and spectral information of the canonical light sources. The proposed method has low complexity and increased applicability. Furthermore, the improvement scheme based on the proposed method has a parallelized structure and can be easily applied to various types of algorithms, such as color constancy, deconvolution, denoising, and contrast enhancement. The algorithms employing the improvement scheme show the potential of the proposed method for solving the problems associated with multiple light sources.
|Number of pages||13|
|Journal||IEEE Transactions on Circuits and Systems for Video Technology|
|Publication status||Published - 2020 Nov|
Bibliographical noteFunding Information:
Manuscript received September 21, 2019; revised November 30, 2019; accepted December 12, 2019. Date of publication December 18, 2019; date of current version October 29, 2020. This work was supported in part by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) under Grant 2019R1A2C2002167 and in part by the Graduate School of YONSEI University Research Scholarship Grants in 2018. This article was recommended by Associate Editor W. Li. (Corresponding author: Moon Gi Kang.) The authors are with the Department of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, South Korea (e-mail: email@example.com).
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All Science Journal Classification (ASJC) codes
- Media Technology
- Electrical and Electronic Engineering