title: Is There A Opencv 2.3 Mat Pointer In C++
body: <p>I'm new in opencv and use the version 2.3 in C++. My approach is to get a float** pointer to the values of a cv::Mat_ where I can also change values or get access via float[][]. I need it to use fftw3 and other stuff, where I usually need those pointers. The documentation of opencv is very nice, but I could just find the uchar* pointer "data". Reading images with this pointer is not a problem, but I also want to write floats or doubles in cv::Mats.</p>
  
  <p>just for help: my final function should look like:</p>
  
  <pre><code>template &lt;typename T&gt; cv::Mat_&lt;complex&lt;T&gt; &gt; fft2 (cv::Mat_&lt;T&gt; input)
  </code></pre>
  
  <p>So has somebody a small code snippet for this problem?</p>