New Post: image.Extent how to get transparent background

I am experimenting with Magick.NET, and am trying to get a transparent background. I can get this to work with code like the following, but I think this is a hack, and not the correct way to do this. What would be the correct way to accomplish this?

MagickImage image = new MagickImage(sPath + "Render3D1.jpg");
image.Resize(300, 300);
image.Format = MagickFormat.Png;
var geometry = new ImageMagick.MagickGeometry(300, 300);
var gravity = new ImageMagick.Gravity();
var backgroundColor = new ColorMono(false); //* Hack??
gravity = Gravity.Center;
image.Extent(geometry, gravity, backgroundColor);
image.Write(sPath + "Render3D1_300_WthGeometry.png");