Invertible color-to-monochrome transformation based on clustering with lightness constraint

To generate a monochrome image from a color one, usually, lightness components of the color image are extracted and used. This transformation is generally not invertible and it is impossible to reconstruct the original color information from a yielded monochrome image. In this paper, we propose an invertible color-to-monochrome transform method obtaining the monochrome image which contains the color information and enables us to reconstruct a color image. In the proposed method, colors in an input image are clustered by k-means-based algorithm with a lightness constraint, and the output monochrome image is obtained using the clustering result.