The PutImage() method is called with a StereoImage object as sole parameter, and returns a boolean value indicating if the StereoImage was successfully output. A return value of false indicates that the StereoImage couldn't be output due to normal conditions, specifically, attempting to output more StereoImages than the Output object can handle.
The FinaliseImage() method is called with the final StereoImage object, when the upstream Input module returns NULL. This allows the Output module to perform any final output tasks before its destructor is called. A default implementation, of simply doing nothing, is provided in Output.
When Output objects are created they are passed the dimensions of the images they can expect to receive. This allows some state to be initialised before any images have been output, for example, creating an X11 window of the correct size.