Directed color transfer for low-light image enhancement

Abstract

Underexposed, low-light, images are acquired when scene illumination is insufficient for a given camera. Camera limitation originates in the high chance of producing motion blurred images due to shaky hands. In this paper we suggest to actively use underexposing as a measure to prevent motion blurred images to appear and propose a novel color transfer as a method for low light image amplification. The proposed solution envisages a dual acquisition, containing a normally exposed, possibly blurred image and an underexposed/low-light, but sharp one. Good colors are learned from the normal exposed image and transferred to the low light one using a framework matching solution. To ensure that the transfer is spatially consistent, the images are divided into luminance perceptual consistent patches called frameworks and the optimal mapping is piece-wise approximated. The two image may differ by colors and subject to improve the robustness of the spatial matching, we added supplementary extreme channels. The proposed method shows robust results from both an objective and a subjective point of view.