title: Undefined variable "images" or class "images.internal.imapplymatrixc"
body: <p>I am using MATLAB 2014b and tried these commands: </p>
  
  <pre><code>RGB = imread('peppers.png');
  imshow(RGB)
  I = rgb2gray(RGB);
  </code></pre>
  
  <p>But I get this error: </p>
  
  <pre><code>Undefined variable "images" or class "images.internal.imapplymatrixc".
  
  Error in images.internal.imapplymatrixAlgo (line 91)
  Z = images.internal.imapplymatrixc(I, multiplier', constants, outputClass);
  
  Error in rgb2gray (line 64)
      I = images.internal.imapplymatrixAlgo(coef, X, class(X));
  </code></pre>
  
  <p>Any idea?</p>