Multi-layer filtering approach for map images

Raster map image is an important set of color images with similar patterns and textures presented in a limited number of colors. Manipulating this class of color images using conventional image filters may lead to a severe over-filtering problem, by which important details structures are over eliminated or degraded. Even if the statistical based algorithms have been recognized as a set of most efficient filters, their exponentially high memory consumption and computational cost can make them intractable in practice. To solve this operational difficulty, this work proposed a novel multi-layer image filtering approach transforming map image filtering into binary domain. It consists of three intuitive image operators: layer decomposition, binary image filters and layer merging. Experimental results demonstrated that the new proposed approach is very efficient for filtering of raster map image.