title: Python equivalent of matlab corr2
body: <p>I want to know what is the python equivalent of the matlab function corr2 that gives the correlation coefficient between 2 matrices, return only one value.</p>
  
  <p><a href="http://www.mathworks.com/help/images/ref/corr2.html" rel="nofollow">http://www.mathworks.com/help/images/ref/corr2.html</a></p>
  
  <p>I only found that the equivalent in python is scipy.signal.correlate2d but this returns an array.</p>
  
  <p>Thanks.</p>