Border is drawn around the ellipse, how to fill now?

In this tutorial, an ellipse will be outlined. As you can see, a red border will be drawn around. Form such result, how can we fill such surrounded border with white, and the rest of the image as black?

Thanks.

Answer 1

[Chad Greene]

You could fill the ellipse with a patch or you could use inpolygon to set all pixels inside the polygon to one color, and set all other pixels another color.