codice:
//-------------------------------------------------------------------------
//questa procedura, data una immagine bmpSource, la ritaglia secondo il
//rettangolo clip passato
//-------------------------------------------------------------------------
public static void ImgClip(ref Bitmap bmpSource, Rectangle clip)
{
Bitmap bmp = new Bitmap(clip.Width, clip.Height, bmpSource.PixelFormat);
bmp.SetResolution(bmpSource.HorizontalResolution, bmpSource.VerticalResolution);
Graphics gr = Graphics.FromImage(bmp);
gr.Clear(Color.White);
//'imposto lavoro alta qualità
gr.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
gr.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
gr.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
gr.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
gr.DrawImage(bmpSource, new Rectangle(0, 0, clip.Width, clip.Height), clip, GraphicsUnit.Pixel);
gr.Dispose();
bmpSource.Dispose();
bmpSource = bmp;
}