message: Output RGBA images when bayer_xx2YYYA is called
diff: @@ -1686,8 +1686,11 @@ void cv::demosaicing(InputArray _src, OutputArray _dst, int code, int dcn)
  CV_Error(CV_StsUnsupportedFormat, "Bayer->Gray demosaicing only supports 8u and 16u types");
  break;
  - case CV_BayerBG2BGR: case CV_BayerGB2BGR: case CV_BayerRG2BGR: case CV_BayerGR2BGR:
  case CV_BayerBG2BGRA: case CV_BayerGB2BGRA: case CV_BayerRG2BGRA: case CV_BayerGR2BGRA:
  + if (dcn <= 0)
  + dcn = 4;
  + /* fallthrough */
  + case CV_BayerBG2BGR: case CV_BayerGB2BGR: case CV_BayerRG2BGR: case CV_BayerGR2BGR:
  case CV_BayerBG2BGR_VNG: case CV_BayerGB2BGR_VNG: case CV_BayerRG2BGR_VNG: case CV_BayerGR2BGR_VNG:
  {
  if (dcn <= 0)
  