Delphi, Fast loading of pixel data into TBitmap object from Array of Bytes

Below are 2 procedures which quickly copy Bitmap to Bytes Array, and Bytes Array to Bitmap:
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type
  TMyByteArray = array of Byte;

var
  MyBytes: TMyByteArray;

function BytesPerPixel(APixelFormat: TPixelFormat): Integer;
begin
  Result := -1;
  case APixelFormat of
    pf8bit: Result := 1;
    pf16bit: Result := 2;
    pf24bit: Result := 3;
    pf32bit: Result := 4;
  end;
end;

procedure BitmapToBytes(Bitmap: TBitmap; out Bytes: TMyByteArray);
var
  BytesPerLine: Integer;
  Row, Col, BPP: Integer;
  PPixels, PBytes: Pointer;
begin
  BPP := BytesPerPixel(Bitmap.PixelFormat);
  if BPP < 1 then
    raise Exception.Create('Unknown pixel format');
  SetLength(Bytes, Bitmap.Width * Bitmap.Height * BPP);
  BytesPerLine := Bitmap.Width * BPP;
  for Row := 0 to Bitmap.Height-1 do
  begin
    PBytes := @Bytes[Row * BytesPerLine];
    PPixels := Bitmap.ScanLine[Row];
    CopyMemory(PBytes, PPixels, BytesPerLine);
  end;
end;

procedure BytesToBitmap(const Bytes: TMyByteArray; Bitmap: TBitmap;
  APixelFormat: TPixelFormat; AWidth, AHeight: Integer);
var
  BytesPerLine: Integer;
  Row, Col, BPP: Integer;
  PPixels, PBytes: Pointer;
begin
  BPP := BytesPerPixel(APixelFormat);
  if BPP < 1 then
    raise Exception.Create('Unknown pixel format');
  if (AWidth * AHeight * BPP) <> Length(Bytes) then
    raise Exception.Create('Bytes do not match image properties');
  Bitmap.Width := AWidth;
  Bitmap.Height := AHeight;
  Bitmap.PixelFormat := APixelFormat;
  BytesPerLine := Bitmap.Width * BPP;
  for Row := 0 to Bitmap.Height-1 do
  begin
    PBytes := @Bytes[Row * BytesPerLine];
    PPixels := Bitmap.ScanLine[Row];
    CopyMemory(PPixels, PBytes, BytesPerLine);
  end;
end;
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Here is sample usage:
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procedure TForm1.Button1Click(Sender: TObject);
begin
  BitmapToBytes(Image1.Picture.Bitmap, MyBytes);
  BytesToBitmap(MyBytes, Image2.Picture.Bitmap,
    Image1.Picture.Bitmap.PixelFormat,
    Image1.Picture.Bitmap.Width,
    Image1.Picture.Bitmap.Height);
end;
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