Yes extremely silly of me. Reminds me of tracing 2D cells with NeuronJ, yet it didn't twig. Working well now albeit a bit slow. Is there anyway to improve the stability of the program? I'm not CPU (Ive noticed it only utilises one core) or memory bound but I get a lot of freezing and crashes with some of the, I'm guessing, more computationally complex tasks. 

Sure I'd love to hear more about it. Really want to find a smart way to process this 5D data...