Michael H. F. WilkinsonGeneralized Pattern Spectra Sensitive to Spatial Information.21-242002conf/icpr/2002ICPR (1)https://doi.org/10.1109/ICPR.2002.1044579https://doi.ieeecomputersociety.org/10.1109/ICPR.2002.1044579db/conf/icpr/icpr2002-1.html#Wilkinson02