.....
Picture.LoadFromFile('image.png');
.....
Bitmap.Canvas.Draw(50,50,Picture.Graphic);
.....
BitBlt(Form1.Image321.Bitmap.Handle,0,0,Bitmap.Width,Bitmap.Height,Bitmap.Handle,0,0, SRCCOPY);
...

  //////////////РИСУЕТ НА КАНВАСЕ
  image321.Canvas.Pen.Color:=clred;
  image321.Canvas.Pen.Width:=3;
  image321.Canvas.Polygon(b);

 //////////////РИСУЕТ НА БИТМАПЕ
    Image321.Bitmap.BeginUpdate;
    try
      begin
        FCanvas := TCanvas32.Create(Image321.Bitmap);
        FCanvas.Brushes.Add(TSolidBrush);
        FSolid := TSolidBrush(FCanvas.Brushes[0]);
        FSolid.FillColor := SetAlpha(clred32, 500);
        FCanvas.Path.LineTo(B[0].X, B[0].Y);
        FCanvas.Path.LineTo(B[1].X, B[1].Y);
        FCanvas.Path.LineTo(B[2].X, B[2].Y);
        FCanvas.Path.ClosePath;
        FCanvas.Path.EndPath;
      end;
    finally
      Image321.Bitmap.EndUpdate;
    end;
    Image321.Bitmap.Changed;
    Image321.Refresh; // force repaint

Form1.Image321.Bitmap

image321.Canvas