Private Declare Function SetPixelV Lib "gdi32" (ByVal hdc As Long, ByVal X As _
  Long, ByVal Y As Long, ByVal crColor As Long) As Long
Private Declare Function BitBlt Lib "gdi32" (ByVal hDestDC As Long, ByVal X As _
Long, ByVal Y As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal _
hSrcDC As Long, ByVal XSrc As Long, ByVal YSrc As Long, ByVal dwRop As Long) As _
Long
Private Declare Function CreateCompatibleDC Lib "gdi32" (ByVal hdc As Long) As _
Long
Private Declare Function DeleteDC Lib "gdi32" (ByVal hdc As Long) As Long
Private Declare Function SelectObject Lib "gdi32" (ByVal hdc As Long, ByVal _
  hObject As Long) As Long
Private Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As _
Long
Private Declare Function CreateCompatibleBitmap Lib "gdi32" (ByVal hdc As Long, _
ByVal nWidth As Long, ByVal nHeight As Long) As Long

Dim memHDC As Long
Dim memBitmap As Long
 
Picture1.AutoRedraw = True
 
' PicHeight und PicWidth ist die jeweilige Höhe und Breite von Picture1 in Pixel
 
memHDC = CreateCompatibleDC(Picture1.hdc)
memBitmap = CreateCompatibleBitmap(Picture1.hdc, PicWidth, PicHeight)
Call DeleteObject(SelectObject(memHDC, memBitmap))
Call BitBlt(memHDC, 0, 0, PicWidth, PicHeight, picOutput.hdc, 0, 0, vbSrcCopy)
 
' ... Berechnung
Call SetPixelV(memHDC, ' ...
' ... Berechnung
 
DoEvents
Call BitBlt(Picture1.hdc, 0, 0, PicWidth, PicHeight, memHDC, 0, 0, vbSrcCopy)
Call DeleteObject(memBitmap)
Call DeleteDC(memHDC)
Set Picture1.Picture = Picture1.Image