Figure 4. Scattergrams of spectral feature space of the two new three-band images derived from their
original seven-band images showing well-separated water, urban and vegetation classes: (a) SAVI
(x-axis)-NDBI (y-axis), (b) NDBI (x-axis)-MNDWI (y-axis), (c) SAVI (x-axis)-MNDWI (y-axis) spaces of the
Quanzhou image, (d) NDBI (x-axis)-SAVI (y-axis), (e) NDBI (x-axis)-MNDWVI (y-axis), and (f) SAVI (x-axis)-
MNDWI (y-axis) spaces of the Fuzhou image.