Currently there is only one input 
processing
output stream present in the system. However, the motivation for having more
is that the ilViewer class utilised in the OutputIlStereo module can very easily
display any number of arbitrary images. As such, it might be possible to have
several of these streams proceeding together, with the output window displaying
all of them together. Output module which cannot handle more than one input
stream may have their input streams blended in some manner, for example, by
tiling the images from the input streams in a mosaic.
However, this would require far-reaching changes throughout the framework, including changes to the method of specifying modules and parameters and the way the Images pass through the system in their currently straightforward fashion.