Color by linear neighborhood embedding

This paper presents a new semiautomatic method for adding colors to monochrome images. The new method, termed color by linear neighborhood embedding (CLNE) first computes the geometry of local image patches in the monochrome image and then transmits the geometry to the chrominance. Following computational methods of the locally linear embedding (LLE) algorithm, we compute the geometry of the monochrome image by solving a constrained least squares problem and embed the computed geometry in the chrominance images by solving a linearly constrained quadratic optimization problem, both in closed forms. We also show that the computed geometry of different color channels are highly correlated thus empirically supporting methods that embed the geometry of the monochrome in the chrominance for colorization.