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Proceedings Paper

Exposure-adaptive color-image enhancement
Author(s): Jae-Hyun Kwon; Wonhee Choe; Kangeui Lee; SeongDeok Lee
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Paper Abstract

In many cases, it is not possible to faithfully capture shadow and highlight image data of a high dynamic range (HDR) scene using a common digital camera, due to its narrow dynamic range (DR). Conventional solutions tried to solve the problem with an captured image which has saturated highlight and/or lack of shadow information. In this situation, we introduce a color image enhancing method with the scene-adaptive exposure control. First, our method recommends an optimal exposure to obtain more information in highlight by the histogram-based scene analysis. Next, the proposed luminance and contrast enhancement is performed on the captured image. The main processing consists of luminance enhancement, multi-band contrast stretching, and color compensation. The luminance and chrominance components of input RGB data is separated by converting into HSV color space. The luminance is increased using an adaptive log function. Multi-band contrast stretching functions are applied to each sub-band to enhance shadow and highlight at the same time. To remove boundary discontinuities between sub-bands, the multi-level low-pass filtering is employed. The blurred image data represents local illumination while the contrast-stretched details correspond to reflectance of the scene. The restored luminance image is produced by the combination of multi-band contrast stretched image and multilevel low-pass filtered image. Color compensation proportional to the amount of luminance enhancement is applied to make an output image.

Paper Details

Date Published: 19 January 2009
PDF: 10 pages
Proc. SPIE 7250, Digital Photography V, 72500V (19 January 2009); doi: 10.1117/12.806065
Show Author Affiliations
Jae-Hyun Kwon, Samsung Advanced Institute of Technology (South Korea)
Wonhee Choe, Samsung Advanced Institute of Technology (South Korea)
Kangeui Lee, Samsung Advanced Institute of Technology (South Korea)
SeongDeok Lee, Samsung Advanced Institute of Technology (South Korea)


Published in SPIE Proceedings Vol. 7250:
Digital Photography V
Brian G. Rodricks; Sabine E. Süsstrunk, Editor(s)

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