A feature space plot is similar to a scattergram. It plots the frequency of occurrance of brightness value pairs in the two-dimensional feature space of defined by two images. The input images are usually two bands of multispectral imagery, but any two overlapping images with the same dimensions can be used. The higher the frequency of a value pair, the brighter it is represented in the feature space plot. Note that this tool provides a means of visualizing the relation between two raster images, which is often the necessary step before either correlation analysis or regression analysis. The tool is intended to work with images of an integer data type, or with images with a float data type that have a large enough range that they can be rounded to integer values in a meaningful way.
The following is an example of a Python script that uses this tool:
wd = pluginHost.getWorkingDirectory()
inputFile = wd + "input.dep"
outputFile = wd + "output.dep"
args = [inputFile, outputFile]
pluginHost.runPlugin("FeatureSpacePlot", args, False)
This is a Groovy script also using this tool:
def wd = pluginHost.getWorkingDirectory()
def inputFile = wd + "input.dep"
def outputFile = wd + "output.dep"
String[] args = [inputFile, outputFile]
pluginHost.runPlugin("FeatureSpacePlot", args, false)