// Following code derives a cutout bitmap using a
// scizzor path as a clipping region (like Paint would do)
// Result bitmap has a minimal suitable size, pixels outside
// the clipping path will be white.
public static Bitmap ApplyScizzors(Bitmap bmpSource, List<PointF> pScizzor)
{
GraphicsPath graphicsPath = new GraphicsPath(); // specified Graphicspath
graphicsPath.AddPolygon(pScizzor.ToArray()); // add the Polygon
var rectCutout = graphicsPath.GetBounds(); // find rectangular range
Matrix m = new Matrix();
m.Translate(-rectCutout.Left, -rectCutout.Top); // translate clip to (0,0)
graphicsPath.Transform(m);
Bitmap bmpCutout = new Bitmap((int)(rectCutout.Width), (int)(rectCutout.Height)); // target
Graphics graphicsCutout = Graphics.FromImage(bmpCutout);
graphicsCutout.Clip = new Region(graphicsPath);
graphicsCutout.DrawImage(bmpSource, (int)(-rectCutout.Left), (int)(-rectCutout.Top)); // draw
graphicsPath.Dispose();
graphicsCutout.Dispose();
return bmpCutout;
}