[NumLock]

Код:

type
  TForm1 = class(TForm)
    Image1: TImage;
    procedure FormCreate(Sender: TObject);
...
procedure TForm1.FormCreate(Sender: TObject);
var
  Bitmap: TBitmap;
begin
  Width:=Screen.Width;
  Height:=Screen.Height;
  Left:=0;
  Top:=0;
  Image1.Width:=ClientWidth-Image1.Left shl 1;
  Image1.Height:=ClientHeight-Image1.Top shl 1;
  Bitmap:=TBitmap.Create;
  try
    Bitmap.LoadFromFile('Безымянный.bmp');
    SetStretchBltMode(Image1.Canvas.Handle, HALFTONE);
    StretchBlt(Image1.Canvas.Handle, 0, 0, Image1.Width, Image1.Height, Bitmap.Canvas.Handle, 0, 0, Bitmap.Width, Bitmap.Height, SRCCOPY);
  finally
    Bitmap.Free;
  end;
end;

основной момент в коде:

Код:

SetStretchBltMode(Image1.Canvas.Handle, HALFTONE);
StretchBlt(Image1.Canvas.Handle, 0, 0, Image1.Width, Image1.Height, Bitmap.Canvas.Handle, 0, 0, Bitmap.Width, Bitmap.Height, SRCCOPY);