title: convert Qimage to cvMat 64FC3 format
body: <p>i have searched a lot on the internet but i have only found how to convert Qimage to RGB format, i want to convert an Qimage to cv mat format CV_64FC3.
  i have really bad results when i work with CV_8UC3</p>
  
  <p>here is my code :</p>
  
  <pre><code>QImage myImage;
  myImage.load("C://images//PolarImage300915163358.bmp");
  
  QLabel myLabel;
  myLabel.setPixmap(QPixmap::fromImage(myImage));
  
  //myLabel.show();
  
  cv::Mat image1 = QImage2Mat(myImage);
  
  
  
  Mat img;
  
  image1.convertTo(img, CV_64FC3, 1.0 / 255.0);
  </code></pre>
  
  <p>and here is the function that i used :</p>
  
  <pre><code>cv::Mat QImage2Mat(QImage const&amp; src)
  {
       cv::Mat tmp(src.height(),src.width(),CV_8UC3,(uchar*)src.bits(),src.bytesPerLine());
       cv::Mat result; // deep copy just in case (my lack of knowledge with open cv)
       cvtColor(tmp, result,CV_BGR2RGB);
       return result;
  }
  </code></pre>
  
  <p>please help me i m new to both opencv and Qt</p>