This method also fails if bees remain stationary for
long periods of time, as they get slowly integrated into the
adaptive background model.
In a system where the camera remains fixed such as the
one used in this research, background subtraction methods
have the advantage that the only motion will be by the
foreground objects. However, in an outdoor environment like
a beehive, shadows cast by clouds or leaves, and nonforeground
motion such as grass blowing in the wind can
cause pixel intensities to vary from the background model,
leading to false positives.