title: Android - OpenCV BGRA to BGR conversion is very slow
body: <p>Currently we are developing a smartphone app to apply filters on camera frames using opencv. Filters need BGR Mat (edgePreservingFilter function), but the camera gives BGRA pictures.</p>
  
  <p>Using <code>cv::cvtColor(img,img,COLOR_BGRA2BGR)</code> is working to make the conversion but doing it on each frame make the camera view very slow (0.2 fps in average).</p>
  
  <p>We tried other techniques like manual conversion but everytime the conversion is very slow, and we don't know how to fix it / other methodes more suited to give the correct Mat format.</p>
  
  <p>We are using OpenCV 3.2.0 and Android Studio 2.3.3</p>
  
  <p>Thank you in advance for your help !</p>