Luminance-Aware Color Transform for Multiple Exposure Correction

Abstract

Images captured with irregular exposures inevitably present unsatisfactory visual effects, such as distorted hue and color tone. However, most recent studies mainly focus on underexposure correction, which limits their applicability to real-world scenarios where exposure levels vary. Furthermore, some works to tackle multiple exposure rely on the encoder-decoder architecture, resulting in losses of details in input images during down-sampling and up-sampling processes. With this regard, a novel correction algorithm for multiple exposure, called luminance-aware color transform (LACT), is proposed in this study. First, we reason the relative exposure condition between images to obtain luminance features based on a luminance comparison module. Next, we encode the set of transformation functions from the luminance features, which enable complex color transformations for both overexposure and underexposure images. Finally, we project the transformed representation onto RGB color space to produce exposure correction results. Extensive experiments demonstrate that the proposed LACT yields new state-of-the-arts on two multiple exposure datasets.