Optimization based grayscale image colorization

An optimization based interactive grayscale image colorization method is presented in this paper. It is an interactive colorization method, whereas the only thing user need to do is to provide some color hints by scribbling or seed pixels. The main contribution of this paper is that the colorization method greatly reduces computation time with the same good results in image quality by quadtree decomposition based non-uniform sampling. Moreover, by introducing a new simple weighting function to represent intensity similarity in the cost function, annoying color diffusion among different regions is alleviated. Experiments show that this method gives the same good quality of colorized images as the method of Levin et al. with a fraction of the computational cost.