How to get smooth edges in grabcut in Emgu c#

Question

I have done the grabcut implementation interactive in c# but there is one problem which Iam unable to solve. How to smooth the edges. The edges looks rough after applying grabcut. I googled and found out a solution in c++ but I am unable to convert it into c#. Here What I have done so far.

Image<Bgr, Byte> image = new Image<Bgr, Byte>("SourceImage");  
Image<Gray, Byte> mask1 = newMask;//Grabcut mask
Image<Bgr, float> maskF = mask1.Convert<Bgr, float>();
Image<Bgr, float> maskF2 = maskF.Mul(1 / 255);
Image<Bgr, float> imageF = image.Convert<Bgr, float>();
var img= imageF.Mul(maskF).Convert<Bgr, byte>();
Image<Bgr, byte> result3 = new Image<Bgr, byte>(imageSource.Width, imageSource.Height);
imageSource.Copy(result3, newMask);Pictureboxoutput.image=(result3+img).ToBitMap();

OutputImageInputImage