  Automatic identity recognition from ear images represents an active field of
research within the biometric community. The ability to capture ear images from
a distance and in a covert manner makes the technology an appealing choice for
surveillance and security applications as well as other application domains.
Significant contributions have been made in the field over recent years, but
open research problems still remain and hinder a wider (commercial) deployment
of the technology. This paper presents an overview of the field of automatic
ear recognition (from 2D images) and focuses specifically on the most recent,
descriptor-based methods proposed in this area. Open challenges are discussed
and potential research directions are outlined with the goal of providing the
reader with a point of reference for issues worth examining in the future. In
addition to a comprehensive review on ear recognition technology, the paper
also introduces a new, fully unconstrained dataset of ear images gathered from
the web and a toolbox implementing several state-of-the-art techniques for ear
recognition. The dataset and toolbox are meant to address some of the open
issues in the field and are made publicly available to the research community.
