[vtkusers] axes on imagedata graph

[Louis Desjardins]

Hello experts,

So I have created a spectrogram using the vtkImageData dataset.  I then use 
vtkCubeAxesActor2D to create an axes over the imagedata. I have positioned 
the axes through trial and error so that the x-axis corresponds to the y=0 
location on my imagedata..

However there must be a better way to do this?

Thank you!
LD