title: Buffer and memoryview are not contiguous in the same dimension in python
body: <p>I'm new with Python and I've tried to detect an ellipse in the following picture: <a href="https://i.stack.imgur.com/5ybMh.jpg" rel="nofollow noreferrer">https://i.stack.imgur.com/5ybMh.jpg</a></p>
  
  <p>But when I use this code:</p>
  
  <pre><code>import matplotlib.pyplot as plt
  from skimage import io
  from skimage import data, color, img_as_ubyte
  from skimage.feature import canny
  from skimage.transform import hough_ellipse
  
  image_rgb = io.imread('5ybMh.jpg',)
  
  image_gray = color.rgb2gray(image_rgb)
  edges = canny(image_gray, sigma=2.0,
                low_threshold=0.55, high_threshold=0.8)
  
  result = hough_ellipse(edges, accuracy=20, threshold=250,
                         min_size=0, max_size=0)
  result.sort(order='accumulator')
  </code></pre>
  
  <p>I get the ValueError:</p>
  
  <blockquote>
    <p>Buffer and memoryview are not contiguous in the same dimension.</p>
  </blockquote>
  
  <p>I use scikit-image version 0.12.3.
  I think there is a problem with the min_size=0 and max_size=0, but I'm not sure if there is a context between the error an this two parameters. In the doc I couldn't find very helpful informations about the parameters. (<a href="http://scikit-image.org/docs/dev/api/skimage.transform.html?highlight=transform#skimage.transform.hough_ellipse" rel="nofollow noreferrer">http://scikit-image.org/docs/dev/api/skimage.transform.html?highlight=transform#skimage.transform.hough_ellipse</a>) </p>
  
  <p>So can anybody explain me what this error means and if I have to change the parameters, which value they should have?</p>