The parallel curves for (outward) offset 
of an ellipse
with semi-axis lengths 
and 
are given by
 |  |  |
(1)
|
 |  |  |
(2)
|
The plots above show ellipse parallel curves for ellipses with 
and 0.9.
Each parallel curve can be written as an octic algebraic curve in 
and 
.
The plot above shows a close-up for "inward" ellipse parallel curves. Talbot's curve resembles these curves.
