  Ear recognition can be described as a revived scientific field. Ear
biometrics were long believed to not be accurate enough and held a secondary
place in scientific research, being seen as only complementary to other types
of biometrics, due to difficulties in measuring correctly the ear
characteristics and the potential occlusion of the ear by hair, clothes and ear
jewellery. However, recent research has reinstated them as a vivid research
field, after having addressed these problems and proven that ear biometrics can
provide really accurate identification and verification results. Several 2D and
3D imaging techniques, as well as acoustical techniques using sound emission
and reflection, have been developed and studied for ear recognition, while
there have also been significant advances towards a fully automated recognition
of the ear. Furthermore, ear biometrics have been proven to be mostly
non-invasive, adequately permanent and accurate, and hard to spoof and
counterfeit. Moreover, different ear recognition techniques have proven to be
as effective as face recognition ones, thus providing the opportunity for ear
recognition to be used in identification and verification applications.
Finally, even though some issues still remain open and require further
research, the scientific field of ear biometrics has proven to be not only
viable, but really thriving.
