How to put image logo within generated qr code

I make windows application to generate c# qr code

I success to do that but i need to put image in center of generated bar code

But How to do that this is actually my question ?

I work in visual studio 2015 windows form applications

i using messagetoolkitqrcode

My code generated qr code by c# as following :

private void button1_Click(object sender, EventArgs e)  
        {  
            using (SaveFileDialog sv = new SaveFileDialog() { Filter = "JPEG|*.jpg", ValidateNames = true })  
            {  
                if (sv.ShowDialog()==DialogResult.OK)  
                {  
                    MessagingToolkit.QRCode.Codec.QRCodeEncoder encoder = new MessagingToolkit.QRCode.Codec.QRCodeEncoder();  
                    encoder.QRCodeScale = 8;  
                    Bitmap bmp = encoder.Encode(textBox1.Text);  
                    pictureBox1.Image = bmp;  
                    bmp.Save(sv.FileName, ImageFormat.Jpeg);  
                }  
  
            }  
                  
                      
        }  

How to put logo inside my generated bare code as following image

my logo i need to put inside qr bar code is NASA logo when i generate it as following :

AND logo found in path

c/nasa.jpg