The IDLgrWindow::GetContiguousPixels function method returns an array of long integers whose length is equal to the number of colors available in the index color mode (that is, the value of the N_COLORS property).
The returned array marks contiguous pixels with the ranking of the range's size. This means that within the array, the elements in the largest available range are set to zero, the elements in the second-largest range are set to one, etc. Use this range to set an appropriate colormap for use with the SHADE_RANGE property of the IDLgrSurface and IDLgrPolygon object classes.
To get the largest contiguous range, you could use the following IDL command:
result = obj->GetContiguousPixels() Range0 = WHERE(result EQ 0)
A contiguous region in the colormap can be increasing or decreasing in values. The following would be considered contiguous:
Result = Obj->[IDLgrWindow::]GetContiguousPixels()
Returns an array of long integers whose length is equal to the number of colors available in the index color mode.