Convert bitmap to PNG in-memory in C++ (win32)

CByteArray baPicture;
IStream *pStream = NULL;
if (CreateStreamOnHGlobal(NULL, TRUE, &pStream) == S_OK)
{
    if (image.Save(pStream, Gdiplus::ImageFormatPNG) == S_OK)
    {
    ULARGE_INTEGER ulnSize;
        LARGE_INTEGER lnOffset;
        lnOffset.QuadPart = 0;
        if (pStream->Seek(lnOffset, STREAM_SEEK_END, &ulnSize) == S_OK)
        {
            if (pStream->Seek(lnOffset, STREAM_SEEK_SET, NULL) == S_OK)
            {
                baPicture.SetSize(ulnSize.QuadPart);
                ULONG ulBytesRead;
                pStream->Read(baPicture.GetData(), ulnSize.QuadPart, &ulBytesRead);
            }
        }
    }
}
pStream->Release();