How do I convert from PDF to image all in memory?

Q: We use PDFNET SDK 5 for .NET and use the Export function of the
PDFDraw object to write TIFF files.
Question: How can we write directly into a MemoryStream, instead of a
file?

Our code looks like this:

            // PDFDraw class is used to rasterize PDF pages.
            PDFDraw draw = new PDFDraw();

            // DPI
            draw.SetDPI(_objConfig.TIFFResolution);

            // Details-/Qualitätseinstellungen
            ObjSet objHints = new ObjSet();
            Obj objParams = objHints.CreateDict();

            if (_objConfig.TIFFG4)
            {
                // CCIT G4
                objParams.PutNumber("BPC", 1);
            }

            draw.Export(objPage, TempFile, "TIFF", objParams);
            objHints.Dispose();
            draw..Dispose();

The Export() should write into the memory stream, instead of a file.
--------------------

A: There is no method that serializes a bitmap directly to a memory
stream. You could use draw.GetBitmap() then serialize the
'System.Drawing.Bitmap' to a required image format using MS.NET API
(or some other library). Alternatively you could write to a temp file
then load data into a MemoryStream.