Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Photoshop analysis showing selection of the pupil (red hash marks) based on pixel color (A). After expanding and contracting the selection by equal amounts, the hole in the selection caused by the infrared reflection is removed, leaving an accurate outline of the pupil (B). Red coloring was added to aid in visualizing the selection; hash marks are normally white.
