Fade Bitmap In & Out

type
  PRGBTripleArray = ^TRGBTripleArray;
  TRGBTripleArray = array[0..32767] of TRGBTriple;
  
//

// Fade In Bitmap File
procedure FadeIn(ImageFileName: TFileName);
var
  Bitmap, BaseBitmap: TBitmap;
  Row, BaseRow: PRGBTripleArray;
  x, y, step: integer;
begin
  // Preparing the Bitmap
  Bitmap := TBitmap.Create;
  try
    Bitmap.PixelFormat := pf32bit;  // or pf24bit //
    Bitmap.LoadFromFile(ImageFileName);
    BaseBitmap := TBitmap.Create;
    try
      BaseBitmap.PixelFormat := pf32bit;
      BaseBitmap.Assign(Bitmap);
      // Fading //
      for step := 0 to 32 do
      begin
        for y := 0 to (Bitmap.Height - 1) do
        begin
          BaseRow := BaseBitmap.Scanline[y];
          // Getting colors from final image //
          Row := Bitmap.Scanline[y];
          // Colors from the image as it is now //
          for x := 0 to (Bitmap.Width - 1) do
          begin
            Row[x].rgbtRed := (step * BaseRow[x].rgbtRed) shr 5;
            Row[x].rgbtGreen := (step * BaseRow[x].rgbtGreen) shr 5; // Fading //
            Row[x].rgbtBlue := (step * BaseRow[x].rgbtBlue) shr 5;
          end;
        end;
        Form1.Canvas.Draw(0, 0, Bitmap); //  Output new image
        InvalidateRect(Form1.Handle, nil, False);
        // Redraw window //
        RedrawWindow(Form1.Handle, nil, 0, RDW_UPDATENOW);
      end;
    finally
      BaseBitmap.Free;
    end;
  finally
    Bitmap.Free;
  end;
end;

// Fade Out Bitmap File
procedure FadeOut(ImageFileName: TFileName);
var
  Bitmap, BaseBitmap: TBitmap;
  Row, BaseRow: PRGBTripleArray;
  x, y, step: integer;
begin
  // Preparing the Bitmap //
  Bitmap := TBitmap.Create;
  try
    Bitmap.PixelFormat := pf32bit;  // or pf24bit //
    Bitmap.LoadFromFile(ImageFileName);
    BaseBitmap := TBitmap.Create;
    try
      BaseBitmap.PixelFormat := pf32bit;
      BaseBitmap.Assign(Bitmap);
      // Fading //
     for step := 32 downto 0 do
      begin
        for y := 0 to (Bitmap.Height - 1) do
        begin
          BaseRow := BaseBitmap.Scanline[y];
          // Getting colors from final image
          Row := Bitmap.Scanline[y];
          // Colors from the image as it is now
          for x := 0 to (Bitmap.Width - 1) do
          begin
            Row[x].rgbtRed := (step * BaseRow[x].rgbtRed) shr 5;
            Row[x].rgbtGreen := (step * BaseRow[x].rgbtGreen) shr 5; // Fading //
            Row[x].rgbtBlue := (step * BaseRow[x].rgbtBlue) shr 5;
          end;
        end;
        Form1.Canvas.Draw(0, 0, Bitmap);   // Output new image //
        InvalidateRect(Form1.Handle, nil, False);
        // Redraw window //
        RedrawWindow(Form1.Handle, nil, 0, RDW_UPDATENOW);
      end;
    finally
      BaseBitmap.Free;
    end;
  finally
    Bitmap.Free;
  end;
end;

// Fade Out Bitmap Variable
procedure FadeOutBmp(const Bmp: TImage; Pause: Integer);
var
  BytesPorScan, counter, w, h: Integer;
  p: pByteArray;
begin
  if not (Bmp.Picture.Bitmap.PixelFormat in [pf24Bit, pf32Bit]) then
    raise Exception.Create('Error, bitmap format is not supporting.');
  try
    BytesPorScan := Abs(Integer(Bmp.Picture.Bitmap.ScanLine[1]) -
      Integer(Bmp.Picture.Bitmap.ScanLine[0]));
  except
    raise Exception.Create('Error!!');
  end;

  for counter := 1 to 256 do
  begin
    for h := 0 to Bmp.Picture.Bitmap.Height - 1 do
    begin
      P := Bmp.Picture.Bitmap.ScanLine[h];
      for w := 0 to BytesPorScan - 1 do
        if P^[w] > 0 then P^[w] := P^[w] - 1;
    end;
    Sleep(Pause);
    Bmp.Refresh;
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  FadeOut('Apple.bmp');
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  FadeIn('Apple.bmp');
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  FadeOutBmp(Image1, 1);
end;