As part of phase 1 of our project we’ve looked into using the aerial images to be able to determine percentage cover of bare soil, exposed areas of rock and scree, as well as established vegetation. These can be considered important features to identify when surveying as they may influence the diversity of invertebrate species within the site of study.
For our percentage cover estimations, visual corrections were made to the raw RGB images from all 3 sites and converted into Hue Saturation Brightness (HSB) images using ImageJ within the free Bio7 software. Features were then selected out by thresholding the hue frequency range that the image displays them as. For example, vegetation was shown within the colour ranges of yellow, green and cyan. From there a pixel colour counter plug-in as used to determine how many pixels across the entire image represented the selected feature.
From the images processed we’ve seen that the bench site has a variation in soil, rock and vegetation percentage covers, whereas both meadow sites are unsurprisingly vegetation dominated. There are relatively few patches within the meadows where any rock or bare soil can be seen. At the meadow sites, these features appeared more at the edges of the meadow and where there was the occasion ant hill within the meadow.