Leonardo Guerreiro Azevedo Ralf Hartmut Güting Rafael Brand Rodrigues Geraldo Zimbrão Jano Moreira de Souza Filtering with raster signatures. 187-194 2006 conf/gis/2006 GIS http://doi.acm.org/10.1145/1183471.1183503 db/conf/gis/gis2006.html#AzevedoGRZS06