ABSTRACT
This chapter focuses on the state of the art for the problem of ancient digital mosaic creation. It surveys a unified framework several methods to transform raster input images into good-quality mosaics. The chapter presents the crystallization mosaic techniques, the ancient mosaic methods, and the problem in a three-dimensional environment. The relative performances with respect to the computational complexity have to be taken into account for an effective evaluation and classification. Many sophisticated mosaic approaches adopt smart strategies using computational geometry together with image processing. These techniques generally lead to mosaics that simulate the typical effect of some glass windows in the churches. The chapter summarizes the key of any technique aimed at the production of digital ancient mosaics is clearly the tile positioning and orientation. A discussion of the weakness and the strong points of each method are provided and the relationships between algorithmic choices and visual qualities of the resulting images are emphasized.
