new_contents: import numpy as np
  from skimage import data
  import matplotlib.pyplot as plt
  from skimage import io
  from skimage.feature import hessian_matrix, hessian_matrix_eigvals, hessian_matrix_det
  from skimage.filters import gaussian_filter
  from skimage.morphology import watershed, closing, opening
  from scipy.stats import logistic
  
  
  filename = "skeletons & matching cropped pics/cropped pics/v018-penn.9-1uB2D2-cropm.png"
  
  coins = io.imread(filename)
  coins = (np.mean(coins) - coins) / np.std(coins)
  
  
  sigma = 1.
  
  Hxx, Hxy, Hyy = hessian_matrix(coins, sigma=sigma, mode="wrap")
  
  
  e1, e2 = hessian_matrix_eigvals(Hxx, Hxy, Hyy)
  
  # How much bigger is the first eigenvalue's magnitude
  # compared with the second?
  
  condition = abs(e1/e2)
  
  out = logistic.cdf(np.log(condition))
  
  markers = np.zeros_like(out)
  markers[out < 0] = 1
  markers[out > np.percentile(out, 90)] = 2
  
  plt.imshow(out)
  plt.set_cmap('binary')
  plt.colorbar()
  plt.show()
  
  
subject: Add python eigenvalue code