Hi,
im Speicher. Du musst einen (zu deiner Bitmap) kompatiblen Gerätekontext im Speicher erzeugen via _WinAPI_CreateCompatibleDC oder _GDIPlus_GraphicsCreateFromHDC/HWND
#include <GuiConstantsEx.au3>
#include <GDIPlus.au3>
#include <WinAPI.au3>
#include <ScreenCapture.au3>
Opt('MustDeclareVars', 1)
[/autoit] [autoit][/autoit] [autoit]Global Const $HWND_DESKTOP = 0
[/autoit] [autoit][/autoit] [autoit]_Main()
[/autoit] [autoit][/autoit] [autoit]Func _Main()
Local $hdc, $hdcMem, $hImage, $hGraphic
; Capture top left corner of the screen
_ScreenCapture_Capture (@MyDocumentsDir & "\GDIPlus_Image.jpg", 0, 0, 400, 300)
; Initialize GDI+ library and load image
_GDIPlus_Startup ()
$hImage = _GDIPlus_ImageLoadFromFile (@MyDocumentsDir & "\GDIPlus_Image.jpg")
$hdc = _WinAPI_GetDC ($HWND_DESKTOP)
$hdcMem = _WinAPI_CreateCompatibleDC ($hdc)
_WinAPI_ReleaseDC ($HWND_DESKTOP, $hdc)
$hGraphic = _GDIPlus_GraphicsCreateFromHDC ($hdcMem)
; Draw 2x zoomed image
_GDIPlus_GraphicsDrawImageRectRect ($hGraphic, $hImage, 0, 0, 200, 200, 0, 0, 400, 300)
; Release resources
_GDIPlus_GraphicsDispose ($hGraphic)
_GDIPlus_ImageDispose ($hImage)
_WinAPI_DeleteDC ($hdcMem) ; Gerätekontext wieder freigeben
_GDIPlus_Shutdown ()
; Clean up screen shot file
FileDelete(@MyDocumentsDir & "\GDIPlus_Image.jpg")
; Loop until user exits
Do
Until GUIGetMsg() = $GUI_EVENT_CLOSE
EndFunc ;==>_Main
[/autoit] [autoit][/autoit] [autoit][/autoit]
Gruß
Greenhorn
Mit dem Prinzip des Double-Buffering natürlich, du musst sie ja nicht auf ein Graphics von einer GUI o.ä. zeichnen
[autoit]
_GDIPlus_ImageGetGraphicsContext
_GDIPlus_BitmapCreateFromGraphics
... oder so. GDI+ ist nicht meine Stärke ... 
Gruß
Greenhorn
Probiere es mal damit:
;coded by UEZ 2011
#include <GDIPlus.au3>
$file = FileOpenDialog("Select an image", "", "Images (*.jpg;*.png;*bmp;*gif,*.tif)")
If @error Then Exit
_GDIPlus_Startup()
$hImage = _GDIPlus_ImageLoadFromFile($file)
$newBitmap = Scale_Image($hImage, 320, 256)
_GDIPlus_ImageSaveToFile($newBitmap, @ScriptDir & "\Test.jpg")
ShellExecute(@ScriptDir & "\Test.jpg")
Func Scale_Image($hImage, $newW, $newH)
Local $newImage = _GDIPlus_BitmapCreateFromScan0($newW, $newH)
Local $hContext = _GDIPlus_ImageGetGraphicsContext($newImage)
_GDIPlus_GraphicsSetInterpolationMode($hContext, 7)
_GDIPlus_GraphicsDrawImageRect($hContext, $hImage, 0, 0, $newW, $newH)
_GDIPlus_GraphicsDispose($hContext)
Return SetError(0, 0, $newImage)
EndFunc
Func _GDIPlus_BitmapCreateFromScan0($iWidth, $iHeight, $iStride = 0, $iPixelFormat = 0x0026200A, $pScan0 = 0)
Local $aResult = DllCall($ghGDIPDll, "uint", "GdipCreateBitmapFromScan0", "int", $iWidth, "int", $iHeight, "int", $iStride, "int", $iPixelFormat, "ptr", $pScan0, "int*", 0)
If @error Then Return SetError(@error, @extended, 0)
Return $aResult[6]
EndFunc ;==>_GDIPlus_BitmapCreateFromScan0
Func _GDIPlus_GraphicsSetInterpolationMode($hGraphics, $iInterpolationMode)
Local $aResult = DllCall($ghGDIPDll, "uint", "GdipSetInterpolationMode", "hwnd", $hGraphics, "int", $iInterpolationMode)
If @error Then Return SetError(@error, @extended, False)
Return $aResult[0] = 0
EndFunc ;==>_GDIPlus_GraphicsSetInterpolationMode
Gruß,
UEZ
ich glaube ich versteh das jetzt. thx @ all, ihr habt mir weitergeholfen 
