A morphological opening operation is applied on DSMD, which is defined by the
function DS(ES(DSMD)) and executes an erosion followed by dilation. The kernel is parameterized
at 10 × 10 pixels, corresponding to 25 m2 or the minimum area of a living room
and kitchen for a household (Stad Gent 2004). After morphological filtering, most linear
artefacts and insignificant clusters are removed from the change map (see Figure 8).