  Grid peeling is the process of repeatedly removing the convex hull vertices
of the grid-points that lie inside a given convex curve. It has been
conjectured that, for a more and more refined grid, grid peeling converges to a
continuous process, the affine curve-shortening flow, which deforms the curve
based on the curvature. We prove this conjecture for one class of curves,
parabolas with a vertical axis, and we determine the value of the constant
factor in the formula that relates the two processes.
