not properly updating image from DataGridView in winform application

[jaseem0712]

I have a DataGridView, which has a image column:
Update Button_Click:

 Dim dtimage As Image
    {
        using (MemoryStream ms = new MemoryStream(rv.Row.Field<byte[]>("empimage"))) {
            dtimage = new Bitmap(ms);
        }
    }

Update query:

adapter.UpdateCommand == new SqlCommand("update DepartmentMaster_tbl set dtName = @dtName,dtPhone = @dtPhone,dtEmail = @dtEmail,empimage=@dtimage  where dtId=@dtid", con.connect)

Then I'am converting the image, so that I can save it to my SQL-Server

MemoryStream md = new MemoryStream();
dtimage.Save(md, System.Drawing.Imaging.ImageFormat.Gif);
byte[] bmpBytes = md.GetBuffer();
adapter.UpdateCommand.Parameters.AddWithValue("@dtimage", bmpBytes);
adapter.UpdateCommand.ExecuteNonQuery();

I'm not getting any error after executing this. The image is saved as some black color:[IMG]

[/IMG]