Blood vessel patterns and thermal imaging of ear biometricsTo determine whether a person is who he says he is, has been important since the dawn of man. In ancient Egypt, the Pharaohs measured the height of the persons to identify them. Through the different eras, new ways of authentication have been introduced. All of these are based on either something you have, know or are. In computer science, the examples of something you have can be a smart card or a token of some sort. Something you know can be a password, pass phrase or some secret way of logging into a system. The last category, something you are, is very much biometric oriented and includes e.g. fingerprints, iris and facial features. During the late 1960's, new biometric devices were made to measure different body parts for identification. From that time on, much research has been done in this area and today many such methods are commonly used.
To authenticate a person by something he is will be the focus of this project. Facial recognition has been discussed for quite some time now, but a relatively new and undocumented area in relation to this, ear recognition, will be the topic of this master thesis. Different techniques have been deï¬ned for comparing ears. We will look into some of them, and try to find new and better ways of using the ear as a "something you are" measure in respect to authentication.
Face recognition is by now well documented and tested. This require an image of the entire face, and the image must be taken from the front of the person. By just taking the image of an ear, one reduce the size of data that needs to be verified. Ear recognition is though a new ï¬eld of research, and not much work has been done on this topic. Some of the techniques that have been described are weak and do not really give us any reason to believe that ear recognition might be a new, accurate way of authenticating people (PCA only had a 71,6% recognition rate). These methods are very dependent on the quality of the image, if the ear is covered by hair or if the head is tilted either way. There are however some methods that produce better results, e.g. the "Force Field Transformation method". We will look into new methods
that will broaden the area of ear biometrics, and with this master thesis we hope to consolidate ear recognition as a reliable authentication method. By looking at thermal images or blood vessel patterns in the ear, we hope to receive results that are feasible for authentication as well as overcoming the current issues concerning tilting of the head and occlusion by e.g hair.
Ear recognition is a new ï¬eld of interest for authentication researchers. The theories that have already been described by different sources have results that varies from 71% to 99% depending on which theory that is applied. By trying to find new methods for this process, we hope to present ear authentication as a possible supplement to other authentication measures out there. Taking photos of ears is much more comfortable for the person which is to be authenticated than e.g. iris/retina scans or fingerprints. Retina scanning requires the person to look into the camera for a couple of seconds, a process which many people find uncomfortable. Some individuals are reluctant to put their finger on a scanner where plenty of people have had their "dirty" fingers before them. To be authenticated just by a photo of one's ear would be much more people-friendly. It is also easier for the person to "remember" his ear than it is to remember a password, or to bring some sort of token with him. If we can come up with some good results for this new method of ear authentication, a quick picture of a persons ear can be all that is needed for entering a building, getting access to files, or whatever you are protecting.
In order to solve these problems, several research questions need to be addressed.
Hopefully, this master thesis will make ear authentication a hot topic in the near future. By proposing a new method, we hope to come up with results that can be of use for later research. We will use an infrared camera to get photos of different ears. From this we will try to extract the blood vessels that are present in the ear. We choose to take 2D images as this does not require expensive equipment or long time to analyze the images created by such a camera. Thermal images of the ear is also something we will look into. A thermal image might reduce the problem with hair covering the ear. This will be very valuable in terms of passive identification. During active identification this will not pose a problem, as the subject can pull his hair back and proceed with the authentication process. If these two methods can be combined, and give us good results in terms of recognition rates, we will have shown that ear recognition can be a serious challenger for any authentication process.
