Segmented Images Colorization Using Harmony

Abstract

In the colorization process, artists fill image's regions with colors following harmony rules. Some region colorizations are more significant than others. In this paper we introduce a model for computer assisted colorization of segmented images using Itten's proportion contrast. Our model is able to process images composed of totally blank or partially filled regions. Though, each region must be filled with only one color. The user defines sectors representing colors on the chromatic hue wheel and may redefine each color's proportion. Then a set of colors is selected to compute the desired harmony. To proportionally colorize an image, already existing colors can be taken into account or the harmony can be applied only to blank regions. Due to the fact that regions cannot be divided, exact proportion contrast colorization of segmented images is a difficult algorithmic problem. In order to solve this problem we use different strategies and propose different methods to fill the regions. If they exist, exact solutions are proposed, otherwise different approximation methods are used to determinate combinations of colors-regions close to the defined proportions. Once the image is processed, the user can adapt hue (in the chosen sector), saturation and value of each region to enhance the result. Our model is flexible and specifically designed to help artists, illustrators, comics creators or any other user to automatically colorize (partially or totally) their images.