title: Type Casting in ReleaseDataCallback()
body: <p>I am currently learning using openCv to do object detection on IOS, and I meet with a type casting problem.</p>
  
  <p>below is the code:</p>
  
  <pre><code>#pragma mark - Image processing
  
  
  static void ReleaseDataCallback(void  *info, const void *data, size_t size)
  {
  #pragma unused(data)
  #pragma unused(size)
  IplImage *iplImage = info; //here does not work, the xcode show me that "cannot Initialize a variable of type 'IplImage *' (aka '_IplImage *') with an value of type of void *"
  cvReleaseImage(&amp;iplImage);
  }
  </code></pre>
  
  <p>Maybe a stupid question~ but i did search a lot place but cannot find a solution for the problem.</p>
  
  <p>I found a website :</p>
  
  <p><a href="http://www.kobold2d.com/pages/viewpage.action?pageId=919981" rel="nofollow">http://www.kobold2d.com/pages/viewpage.action?pageId=919981</a>
  I tried the suggestion but it does not work)</p>