message: Init params (StereoSGBMParams) in StereoSGBMImpl constructor initialization list
  To improve preformence it is better to init the params (StereoSGBMParams) in the
  initialization list.
diff: @@ -2186,19 +2186,21 @@ class StereoSGBMImpl CV_FINAL : public StereoSGBM
  {
  public:
  StereoSGBMImpl()
  + : params()
  {
  - params = StereoSGBMParams();
  + // nothing
  }
  StereoSGBMImpl( int _minDisparity, int _numDisparities, int _SADWindowSize,
  int _P1, int _P2, int _disp12MaxDiff, int _preFilterCap,
  int _uniquenessRatio, int _speckleWindowSize, int _speckleRange,
  int _mode )
  - {
  - params = StereoSGBMParams( _minDisparity, _numDisparities, _SADWindowSize,
  + : params(_minDisparity, _numDisparities, _SADWindowSize,
  _P1, _P2, _disp12MaxDiff, _preFilterCap,
  _uniquenessRatio, _speckleWindowSize, _speckleRange,
  - _mode );
  + _mode)
  + {
  + // nothing
  }
  void compute( InputArray leftarr, InputArray rightarr, OutputArray disparr ) CV_OVERRIDE
  