can i put bookmark on pictures without changing thair size?

[irandokht]

hi
i want put a bookmark on any of picture in my priject without changing
thair size after save it .
but size of pictures has been change
please help me
i want size dont change
this is my code :

public void imgClass(Image img)
        {

            Graphics g = Graphics.FromImage(img);
            Font f = new Font("Arial",15);
            g.DrawString("my picture", f, Brushes.White,img.Height-250,img.Width-100 );
            pictureBox1.Image = img;
        }

        private void btnBM_Click(object sender, EventArgs e)
        {
           Image i = pictureBox1.Image;
           imgClass(i);
                     
        }

        private void btnSave_Click(object sender, EventArgs e)
        {
            Image i = pictureBox1.Image;
            i.Save("e:\\mypic.jpg");
            MessageBox.Show("picture has been send!");
        }