Colorization is a computerized process of adding color to a monochrome image. The authors have developed colorization algorithms which propagate colors from seeded color pixels. Since those algorithms are constructed based on a region growing approach, failure colorization occurs at the place where a luminance changes intensely such as edge and texture. Although we developed, in the previous work, a partitioning algorithm for preventing the error propagation at edge, numerous color seeds were required for accurate colorization of the image with texture. This paper presents a new algorithm for colorization with texture by blending seeded colors. In our algorithm, the color can be estimated depending on the Euclidean distance and the luminance distance between each pixel to be colorized. It is shown that the proposed approach can be successfully applied to the images with texture by sowing a small number of color seeds.
Takahiko Horiuchi, Hiroaki Kotera, "Colorization for Monochrome Image with Texture" in Proc. IS&T 13th Color and Imaging Conf., 2005, pp 245 - 250, https://doi.org/10.2352/CIC.2005.13.1.art00045