System.Drawing.Image.Dispose C# (CSharp) Method

        public void Dispose()
        {
            this.Dispose(true);

            GC.SuppressFinalize(this);
        }

    private void UploadFile()
    {
        if (iFileUpload.HasFile)
        {
            string Address = "~\\Administrator\\files\\Design\\" + FileName;
            string str     = "";
            str = Server.MapPath(Address);

            iFileUpload.PostedFile.SaveAs(str);


            string s = Server.MapPath("~\\Administrator\\files\\Design\\Default\\" + FileName);
            string d = Server.MapPath("~\\Administrator\\files\\Design\\" + FileName);

            System.Drawing.Image oimg = System.Drawing.Image.FromFile(s);
            System.Drawing.Image nimg = System.Drawing.Image.FromFile(d);

            if (oimg.Size == nimg.Size)
            {
                lbErr.Visible = false;
            }
            else
            {
                nimg.Dispose();
                oimg.Dispose();
                LinkButton1_Click(null, null);
                lbErr.Visible = true;
            }

            nimg.Dispose();
            oimg.Dispose();
        }
    }