C#-Version
public unsafe System.Drawing.Image Bitmap() {
  System.Drawing.Bitmap result = new System.Drawing.Bitmap( ( int )dimensions.width, ( int )dimensions.height );
  System.Drawing.Imaging.BitmapData Information
      = result.LockBits( new System.Drawing.Rectangle( 0, 0, ( int )dimensions.width, ( int )dimensions.height ), System.Drawing.Imaging.ImageLockMode.WriteOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb );
  int x, y, pos;
  for ( y = 0; y < ( int )dimensions.height; y++ ) {
    for ( x = 0; x < ( int )dimensions.width; x++ ) {
      pos = Information.Scan0.ToInt32() + x * 4 + y * Information.Width * 4;
      *( byte* )( pos + 3 ) = pixels[x, y].a;
      *( byte* )( pos + 2 ) = pixels[x, y].r;
      *( byte* )( pos + 1 ) = pixels[x, y].g;
      *( byte* )pos = pixels[x, y].b;
    }
  }
  result.UnlockBits( Information );
  return result;
}

C++-Version
GX_INLINE Gdiplus::Bitmap *Image::Bitmap( void ) const {
  Gdiplus::Bitmap* result = new Gdiplus::Bitmap( ( int )width, ( int )height, PixelFormat32bppPARGB );
  Gdiplus::BitmapData info;
  int x, y, stride;
  byte *ptr, *scan0;
  OpenGX::Pixel currentPixel;
  stride = info.Stride;
  scan0 = ( byte* )info.Scan0;
  result->LockBits( &Gdiplus::Rect( 0, 0, ( int )width, ( int )height ), Gdiplus::ImageLockMode::ImageLockModeRead | Gdiplus::ImageLockMode::ImageLockModeWrite, PixelFormat32bppPARGB, &info );
  for( y = 0; y < ( int )height; y++ ) {
    for( x = 0; x < ( int )width; x++ ) {
      ptr = scan0 + x * 4 + y * stride;
      currentPixel = pixels[x][y];
      *( ptr + 3 ) = currentPixel.a;
      *( ptr + 2 ) = currentPixel.r;
      *( ptr + 1 ) = currentPixel.g;
      *( ptr ) = currentPixel.b;
    }
  }
  result->UnlockBits( &info );
  return result;
}