procedure TForm1.Button1Click(Sender: TObject);
var Bitmap:Tbitmap;  MyRect,MyOther: TRect;
begin
Bitmap:=Tbitmap.Create;
MyRect:=Rect(0,0,100, 200);
MyOther := Rect(0,0,100, 200);
Bitmap.Width:=100;
Bitmap.Height:=200;
Bitmap.Canvas.CopyRect(MyOther, Form1.Canvas, MyRect);
Bitmap.SaveToFile('ok.bmp');
Bitmap.Free;
end;