Mosaic Stylization Using Andamento

In this paper, a study on Andamento, which is a traditional mosaic style, is described and a method for simulating a tile mosaic with various types of Andamento is presented. We classify Andamento according to the characteristics of the tile and represent the characteristics as energy terms. We introduce a method for generating a mosaic of a certain Andamento by minimizing a mosaic energy function composed of a weighted sum of the energy terms. We propose an iterative algorithm for optimizing the energy function, and the algorithm consists of global refinement, which is a heuristic approach, and local refinement optimized by employing an evaluation of the energy function. The global refinement process causes the positions of the tiles to converge quickly toward the direction estimated to reduce the energy function. A local refinement elects the candidates of the edge transform of the tile that are expected to decrease the energy function and then evaluates such function. It optimizes the energy function by selecting an edge transform that reduces the energy function most significantly and applies the transformation. Finally, we introduce some post-processes that add texture effects of a tile and grout space.