Retinex model has been applied to low-light image enhancement in many existing methods.
More appropriate decomposition of a low-light image can help achieve better image
enhancement. In this paper, we propose a new pixel-level non-local Haar transform based
illumination and reflectance decomposition method (NLHD). The unique low-frequency
coefficient of Haar transform on each similar pixel group is used to reconstruct the
illumination component, and the rest of all high-frequency coefficients are employed to …