Hue Preservation using Enhanced Integrated Multi-scale Retinex for Improved Color Correction

m c o R a o p c o t t u f H c a bstract. The images captured by most current digital cameras uffer from a narrow dynamic range that results in poor color fidelity nd perceived image quality. Accordingly, this article proposes an nhanced integrated multi-scale Retinex (IMSR) method in a evice-independent color space, namely, CIELAB, to preserve the ue and obtain a high contrast and naturalness. To achieve the esired objectives, a captured sRGB image is transformed into IELAB color space using standard equations, then the IMSR is pplied to only the L values, thereby preserving the balance of the olor components, hue, and saturation. However, since this process auses unnatural undersaturation, a saturation adjustment is perormed by applying a simple saturation compensation method, hich maintains the chromatic ratio with respect to the sRGB gamut oundary according to the variation in the luminance. The adjusted IELAB values are then transformed into sRGB using an inverse ransform function. In experiments, the proposed method showed an mproved visibility in both dark and bright regions, while reducing olor distortion. Furthermore, in an observation preference test, the mages resulting from the proposed method were perceived as havng a higher visibility and naturalness. © 2011 Society for Imaging cience and Technology. DOI: 10.2352/J.ImagingSci.Technol.2011.55.1.010504