Palette‐Based and Harmony‐Guided Colorization for Vector Icons

Abstract

AbstractColorizing icon is a challenging task, even for skillful artists, as it involves balancing aesthetics and practical considerations. Prior works have primarily focused on colorizing pixel‐based icons, which do not seamlessly integrate into the current vector‐based icon design workflow. In this paper, we propose a palette‐based colorization algorithm for vector icons without the need for rasterization. Our algorithm takes a vector icon and a five‐color palette as input and generates various colorized results for designers to choose from. Inspired by the common icon design workflow, we developed our algorithm to consist of two steps: generating a colorization template and performing the palette‐based color transfer. To generate the colorization templates, we introduce a novel vector icon colorization model that employs an MRF‐based loss and a color harmony loss. The color harmony loss encourages the alignment of the resulting color template with widely used harmony templates. We then map the predicted colorization template to chroma‐like palette colors to obtain diverse colorization results. We compare our results with those generated by previous pixel‐based icon colorization methods and validate the effectiveness of our algorithm by evaluations in both qualitative and quantitative measurements. Our method enables icon designers to explore diverse colorization results for a single icon using different color palettes while also efficiently evaluating the suitability of a color palette for a set of icons.