Pavel Zahradnik Miroslav Vlcek Fast Design of 2-D Narrow Bandstop FIR Filters for Image Enhancement. 726-732 https://doi.org/10.1007/978-3-540-30134-9_97 2004 conf/kes/2004-3 KES db/conf/kes/kes2004-3.html#ZahradnikV04