Single image deraining via decorrelating the rain streaks and background scene in gradient domain.

•We propose a single image de-raining method in gradient domain based on the observation that the influence of rain streaks on X- and Y- gradients shows different statistical properties.•A rain-free direction is first proposed, along which a rain image or a block is least-affected in gradient domain. It is effective in recovering image texture details.•To extract the rain-free gradient along the direction perpendicular to the rain-free one, a novel decomposition model is proposed, which is formulated as an objective function with three terms: an anisotropic total variation term, a low-rank constraint and a de-correlation term.