Bitmap bm = new Bitmap(300,500);
Graphics g = Graphics.FromImage(bm);
g.DrawString("this is a test",new Font("Arial",9),Brushes.Beige,new PointF(20,20));
g.Dispose();
Bitmap b ;
b = bm.Clone(new Rectangle(0,0,150,250),PixelFormat.Format24bppRgb );
b.Save(@"d:\temp\3.bmp");