In this letter, a method is presented to reduce misclassification at t
he boundaries between different types of land covers. Errors are cause
d by use of spatial features extracted from pixel neighbourhoods. Simp
le thresholding and region-growing techniques are used to reduce such
errors. The method is included as an extension to a frequency-based co
ntextual classifier (FBC). Some experiments have been carried out to e
valuate both the original classifier, FBC, and the extended version us
ing an image acquired with a Compact Airborne Spectrographic Imager (C
ASI). Experimental results show that overall classification accuracies
with the CASI image are 84.80 per cent and 89-37 per cent obtained us
ing the FBC and the extended FBC, respectively.