Aerial image analysis was performed using the public domain image analysis software Image-J (NIH) 1. The red/green/blue channels of the images were split and the blue and green channels were subjected to the AND logical operation, the resulting image was then subjected to the logical OR operation with the red channel. The resulting black and white image (Glenorchy BorGandR, below)was threshold into four regions based on the gray level regions indicated from their histogram (see bleow). Three of the threshold regions were then assigned the RGB colours and mixed to generate a false colour image of the open field area RGB Composite2 forb_grass_cespitose.
Table M1: Image analysis of coloured areal pictures. |
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(File Name) |
Logical operations |
Histogram Interpretation |
False colour figure |
(Glenorchy BorGandR)
|
(Blue OR Green) AND Red
|
190 – 255: open ground 120 – 160: tall grasses 90 – 120: cespitose grasses 50 -90: forbs and small shrubs, light foliaged trees. 0 – 50: shrubs and tree with strong shade and shadows |
green: open ground and tall grasses red: forbs, cespitose grasses, (light foliage trees) blue: large shrubs, dark foliage trees.
|