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island areas are present in the vector data). In this way large polygons (with
islands eliminated) matching the deviation from expected mixed forestry values
outlined above can be assumed to be representative of bog. There is probably
some scope for the use of pattern analysis to further refine this search. The
uniform (low standard deviation) values displayed by the bog sample suggest that
it may be possible, once the areas are identified in the automatic search algorithm
suggested in this study, to examine these for rows and machinery tracks to
automatically calculate the level of cutting taking place.
The third sample type taken for comparative analysis with mixed forestry was an
area of cut pasture. This was taken as a control to ensure the previous two samples
matched expected values (in terms of relative percentages) found in the other
survey areas of the image. The high mean pixel values (and low level of standard
deviation) matched expected results in that both the red and green colour bands
showed markedly higher values (see table above). This type of pasture will not be
factored into a proportional value check against mixed forestry in the algorithm as
it can be referenced against the two stable control value sets present in water and
roofs. It should be noted that this particular area type is dependant on the time of
year and weather conditions prior to the time the aerial imagery was flown and is
something that must be included in a second or higher loop of the algorithm.
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