sort the discovered clusters by size of clusters; draw box around two largest
clusters (hopefully) highlighting the Q60 fiducial
animated plot of row-by-row np.diff()  (highly entertaining but only mildly
        useful)
add a state to search for flat spot after the falling edge of the 2nd (white)
    fiducial
if get an RGBA image, convert to RGB (rude, ugly, brute force)
experiment with using correlate() to find the fiducials
plot graphs of correlate() against the Q60 images (tinkering with using correlate() to find the fiducials)