#include <GUIConstantsEx.au3>
#include <ScreenCapture.au3>
#include <WindowsConstants.au3>

AutoItSetOption("GUIOnEventMode", 1)

$Width = @DesktopWidth/2
$Height = @DesktopHeight/2
$Form = GUICreate("GUI", $Width, $Height, -1, -1)
$Pic= GUICtrlCreatePic("", 0, 0, $Width, $Height)
GUISetState(@SW_SHOW)

$hCtrl = GUICtrlGetHandle($Pic)
$hGUI_DC = _WinAPI_GetDC($Form)
$hDC = _WinAPI_GetDC(0)
_WinAPI_SetStretchBltMode($hGUI_DC, $STRETCH_HALFTONE)

GUISetOnEvent($GUI_EVENT_CLOSE, "_Exit")

While 1
    $Timer = TimerInit()
    _WinAPI_StretchBlt($hGUI_DC, 0, 0, $Width, $Height, $hDC, 0, 0, @DesktopWidth, @DesktopHeight, $SRCCOPY)
    ToolTip(TimerDiff($Timer))
WEnd

Func _Exit()
    _WinAPI_ReleaseDC($Form, $hGUI_DC)
    _WinAPI_ReleaseDC(0, $hDC)
    GUIDelete()
    Exit
EndFunc