public static Image StreamToImage(byte[] buff) 
{
MemoryStream ms = new MemoryStream(buff); 
Image img = Image.FromStream(ms);
return img; 
}

Public Shared Function StreamToImage(ByVal buff As Byte()) As Image

    Dim ms As New MemoryStream(buff)

    Dim img As Image = Image.FromStream(ms)
    Return img

End Function

procedure BytesArrayToBitmap(const BytesArray: array of byte; const W, H: integer;
                             const PixelFormat: TPixelFormat; Bitmap: TBitmap);
var TBmp: TBitmap;
    pX : ^byte;
    LZ : integer;
begin
  TBmp := TBitmap.Create;
  try
    case PixelFormat of
      pf8bit : LZ := (Bitmap.Width * Bitmap.Height);
      pf16bit: LZ := (Bitmap.Width * Bitmap.Height) * 2;
      pf24bit: LZ := (Bitmap.Width * Bitmap.Height) * 3;
      pf32bit: LZ := (Bitmap.Width * Bitmap.Height) * 4;
    end;
    TBmp.PixelFormat := PixelFormat;
    TBmp.Width := W;
    TBmp.Height:= H;
    pX := TBmp.ScanLine[TBmp.Height-1];
    CopyMemory(pX, @BytesArray[0], LZ);
    Bitmap.Assign(TBmp);
  finally
    TBmp.Free;
  end;
end;

procedure ByteArray2Bitmap(const aBMP: TBitmap;const ByteArray: Array of Byte);
var MS: TMemoryStream;
begin
  MS := TMemoryStream.Create;
  try
    MS.WriteBuffer(ByteArray[0], Length(ByteArray));
    MS.Seek(0, soFromBeginning);
    aBMP.LoadFromStream(MS);
  finally
    MS.free;
  end;
end;
// Utilisation
procedure TForm1.Button2Click(Sender: TObject);
begin
  ByteArray2Bitmap(Image2.Picture.Bitmap, aBArray);
end;

Private Declare Function SetBitmapBits Lib "gdi32" (ByVal hBitmap As Long, ByVal dwCount As Long, lpBits As Any) As  Long
Sub ArrayToPicture(ByRef byteArray() As Byte, ByRef imgDest As IPicture)
    Call SetBitmapBits(imgDest.handle, UBound(byteArray),  byteArray(0))
End Sub