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Hi, I'm trying to compare two bitmaps (screenshots of the desktop) that I create using BitBlt. The bitmaps can be successfully saved to disk, but when I run the two bitmaps through a CompareBitmaps()-function I found in this thread, which calls memcmp, the script crashes with "Exit code: -1073741819". This crash only happens when I try to compare bitmaps that I got by using BitBlt. If I use the CompareBitmaps()-function on bitmaps created by _GDIPlus_ImageLoadFromFile, everything works fine. (I'm using AutoIT 3.3.6.1) I'll attach my script that crashes, and the CompareBitmaps() example script that works (which I got from the thread previosly mentioned) My script, that for some reason crashes : #include <ScreenCapture.au3> #include <GDIPlus.au3> #include <WinAPI.au3> _GDIPlus_Startup() Local $hDesktop = _WinAPI_GetDesktopWindow() $clientS = WinGetClientSize($hDesktop) Local $Width = $clientS[0] Local $Height = $clientS[1] Local $hDC = _WinAPI_GetDC($hDesktop) Local $memDC = _WinAPI_CreateCompatibleDC($hDC) Local $memBmp = _WinAPI_CreateCompatibleBitmap($hDC, $Width, $Height) _WinAPI_SelectObject ($memDC, $memBmp) _WinAPI_BitBlt($memDC, 0, 0, $Width, $Height, $hDC, 0,0, $__SCREENCAPTURECONSTANT_SRCCOPY) _WinAPI_DeleteDC($memDC) _WinAPI_ReleaseDC($hDesktop, $hDC) Local $hImage1 = _GDIPlus_BitmapCreateFromHBITMAP($memBmp) _WinAPI_DeleteObject($memBmp) _GDIPlus_ImageSaveToFile($hImage1, @ScriptDir & "\GDIPlus_Image1.jpg") MsgBox(0, "Debug", "Screenshot taken & saved to disk. Ready to take new screenshot" ) Local $hDC2 = _WinAPI_GetDC($hDesktop) Local $memDC2 = _WinAPI_CreateCompatibleDC($hDC2) Local $memBmp2 = _WinAPI_CreateCompatibleBitmap($hDC2, $Width, $Height) _WinAPI_SelectObject ($memDC2, $memBmp2) _WinAPI_BitBlt($memDC2, 0, 0, $Width, $Height, $hDC2, 0,0, $__SCREENCAPTURECONSTANT_SRCCOPY) _WinAPI_DeleteDC($memDC2) _WinAPI_ReleaseDC($hDesktop, $hDC2) Local $hImage2 =_GDIPlus_BitmapCreateFromHBITMAP($memBmp2) _WinAPI_DeleteObject($memBmp2) _GDIPlus_ImageSaveToFile($hImage2, @ScriptDir & "\GDIPlus_Image2.jpg") MsgBox(0, "Debug", "Screenshot2 taken & saved to disk. Ready to compare images (from memory)" ) MsgBox(0, "bm1==bm2", CompareBitmaps($hImage1, $hImage2) ) ; Clean up resources _GDIPlus_ImageDispose($hImage1) _GDIPlus_ImageDispose($hImage2) ; Shut down GDI+ library _GDIPlus_ShutDown () Func CompareBitmaps($bm1, $bm2) $Bm1W = _GDIPlus_ImageGetWidth($bm1) $Bm1H = _GDIPlus_ImageGetHeight($bm1) $BitmapData1 = _GDIPlus_BitmapLockBits($bm1, 0, 0, $Bm1W, $Bm1H, $GDIP_ILMREAD, $GDIP_PXF32RGB) $Stride = DllStructGetData($BitmapData1, "Stride") $Scan0 = DllStructGetData($BitmapData1, "Scan0") $ptr1 = $Scan0 $size1 = ($Bm1H - 1) * $Stride + ($Bm1W - 1) * 4 $Bm2W = _GDIPlus_ImageGetWidth($bm2) $Bm2H = _GDIPlus_ImageGetHeight($bm2) $BitmapData2 = _GDIPlus_BitmapLockBits($bm2, 0, 0, $Bm2W, $Bm2H, $GDIP_ILMREAD, $GDIP_PXF32RGB) $Stride = DllStructGetData($BitmapData2, "Stride") $Scan0 = DllStructGetData($BitmapData2, "Scan0") $ptr2 = $Scan0 $size2 = ($Bm2H - 1) * $Stride + ($Bm2W - 1) * 4 $smallest = $size1 If $size2 < $smallest Then $smallest = $size2 $call = DllCall("msvcrt.dll", "int:cdecl", "memcmp", "ptr", $ptr1, "ptr", $ptr2, "int", $smallest) _GDIPlus_BitmapUnlockBits($bm1, $BitmapData1) _GDIPlus_BitmapUnlockBits($bm2, $BitmapData2) Return ($call[0]=0) EndFunc ;==>CompareBitmaps Example Script (that basically does the same thing, but works fine) #include <GDIPlus.au3> _GDIPlus_Startup() $fname1=FileOpenDialog("First image","","All images(*.bmp;*.jpg;*.png;)") If $fname1="" Then Exit $fname2=FileOpenDialog("Second image image","","All images(*.bmp;*.jpg;*.png;)") If $fname2="" Then Exit $bm1 = _GDIPlus_ImageLoadFromFile($fname1) $bm2 = _GDIPlus_ImageLoadFromFile($fname2) MsgBox(0, "bm1==bm2", CompareBitmaps($bm1, $bm2)) _GDIPlus_ImageDispose($bm1) _GDIPlus_ImageDispose($bm2) _GDIPlus_Shutdown() Func CompareBitmaps($bm1, $bm2) $Bm1W = _GDIPlus_ImageGetWidth($bm1) $Bm1H = _GDIPlus_ImageGetHeight($bm1) $BitmapData1 = _GDIPlus_BitmapLockBits($bm1, 0, 0, $Bm1W, $Bm1H, $GDIP_ILMREAD, $GDIP_PXF32RGB) $Stride = DllStructGetData($BitmapData1, "Stride") $Scan0 = DllStructGetData($BitmapData1, "Scan0") $ptr1 = $Scan0 $size1 = ($Bm1H - 1) * $Stride + ($Bm1W - 1) * 4 $Bm2W = _GDIPlus_ImageGetWidth($bm2) $Bm2H = _GDIPlus_ImageGetHeight($bm2) $BitmapData2 = _GDIPlus_BitmapLockBits($bm2, 0, 0, $Bm2W, $Bm2H, $GDIP_ILMREAD, $GDIP_PXF32RGB) $Stride = DllStructGetData($BitmapData2, "Stride") $Scan0 = DllStructGetData($BitmapData2, "Scan0") $ptr2 = $Scan0 $size2 = ($Bm2H - 1) * $Stride + ($Bm2W - 1) * 4 $smallest = $size1 If $size2 < $smallest Then $smallest = $size2 $call = DllCall("msvcrt.dll", "int:cdecl", "memcmp", "ptr", $ptr1, "ptr", $ptr2, "int", $smallest) _GDIPlus_BitmapUnlockBits($bm1, $BitmapData1) _GDIPlus_BitmapUnlockBits($bm2, $BitmapData2) Return ($call[0]=0) EndFunc ;==>CompareBitmaps Any one got a clue why my script crashes?