title: ColorBlobDetector cannot multiply contour
body: <p>I am new to OpenCV and tried to use ColorBlobDetector from the samples of OpenCv, but it returns error in</p>
  
  <pre><code>Core.multiply(contour, new Scalar(4,4), contour);
  </code></pre>
  
  <p>saying "Fatal signal 11 (SIGSEGV), code 1, fault addr 9x9 in tid 10111 (Thread-28303)</p>
  
  <p>I am using eclipse.</p>
  
  <p>I have search for whole day already, can anybody tell me why this error happen and how to fix it? I didn't edit anything in the code.</p>
  
  <p>And I would like to know how can I modify the code so that I can specify the app to detect white contour only from the start of the app?</p>
  
  <p>Thank you.</p>