A Survey on Ear Biometrics

Recognizing people by their ear has recently received significant attention in the literature. Several reasons account for this trend: first, ear recognition does not suffer from some problems associated with other non contact biometrics, such as face recognition; second, it is the most promising candidate for combination with the face in the context of multi-pose face recognition; and third, the ear can be used for human recognition in surveillance videos where the face may be occluded completely or in part. Further, the ear appears to degrade little with age. Even though, current ear detection and recognition systems have reached a certain level of maturity, their success is limited to controlled indoor conditions. In addition to variation in illumination, other open research problems include hair occlusion; earprint forensics; ear symmetry; ear classification; and ear individuality. This paper provides a detailed survey of research conducted in ear detection and recognition. It provides an up-to-date review of the existing literature revealing the current state-of-art for not only those who are working in this area but also for those who might exploit this new approach. Furthermore, it offers insights into some unsolved ear recognition problems as well as ear databases available for researchers

High performance image processing techniques in automated identification systems

This dissertation addresses different image processing problems faced during the development of two different identification systems (i) an automated system for postmortem identification using dental records (dental radiographs), (ii) an automated ear identification system. Automating the postmortem identification of deceased individuals based on dental characteristics is receiving increased attention especially with the large number of victims encountered in mass disasters, as 9/11 attack, and Tsunami. The Automated Dental Identification System (ADIS) can be used by law enforcement agencies to locate missing persons using databases of dental x-rays of human remains and dental scans of missing or unidentified persons. ADIS provides functionality for users to upload the reference records, and submit identification queries using submitted records. ADIS then produces a short matching list of possible matches for the dental experts to verify. The ear identification system can be used at access point of restricted areas; this system helps identify a person from surveillance videotapes.;This dissertation introduces new high performance approaches for three image-processing problems of the ADIS record preprocessing stage. For the first, we introduce an automatic hierarchical approach to the problem of cropping dental image records into films. Our approach is heavily based on concepts of mathematical morphology and shape analysis. Testing reflects an overall error of ∼ 3%. For the second, we address the problem of teeth contour extraction using active contour without edges. This technique is based on the intensity properties of the overall region of the tooth image. It extracts a very smooth and accurate tooth contour. For the third, we enhance the existing techniques for automatic classification of teeth into four classes (molars, premolars, canines, and incisors); as well as the construction of a dental chart, which is a data structure that guides tooth-to-tooth matching. We tackle this composite problem using appearance-based features (low computational-cost) for assigning an initial class, followed by applying a string matching with don\u27t care technique based on teeth neighborhood rules. Adding the don\u27t care character allows the technique to work in the presence of missing tooth, which represents 21% of the database. Our approach achieves 82% teeth labeling accuracy based on a large test dataset of films.;For ADIS, also we introduce new techniques for the problem of fast dental image retrieval. We use Eigen images to reduce the dimensionality of each tooth, as well as other teeth contour descriptors. The main features of this search engine are that it completes the search in order of seconds and it reaches a reasonable accuracy with a relatively short candidate list.;For ear identification, we develop different components of a viable automated method for ear identification system. We automate the Iannarelli ear identification system, which had been used manually for years. We extract the ear external and internal curves, and use these curves to calculate the different Iannarelli distance measurements. We evaluated the system performance based on statistical analysis of a large dataset of thousands ear images, where the identification rate is 90% for rank 1 image

A Survey of NOMA for VLC Systems: Research Challenges and Future Trends

International audienceVisible light communication (VLC) has become a promising technology for high data rate communications and an attractive complementary to conventional radio frequency (RF) communication. VLC is a secure, energy efficient and cost-effective technology that exploits the existing infrastructure, particularly in indoor environments, for wireless data transmission. Nevertheless, the main limitation of developing high data rate VLC links is the narrow modulation bandwidth of light-emitting diodes (LEDs), which is in the megahertz range. The power domain nonorthogonal multiple access (PD-NOMA) scheme is envisioned to address several challenges in VLC systems. In this paper, we present a detailed overview of PD-NOMA based VLC systems. Moreover, we introduce insights on some PD-NOMA VLC system constraints and challenges such as power allocation, clipping effect, MIMO and security. Finally, we provide open research problems as well as possible directions for future research to pave the way for the implementation of PD-NOMA VLC systems

MIMO Techniques for High Data Rate Free Space Optical Communication System in Log-Normal Channel

International audienceAbstract--Multiple input multiple output (MIMO) technique with equal gain combining (EGC) is considered in this work to enhance the data rate of free-space optical communication (FSO) system in log-normal channel. In FSO system, light propagating in free space is used to transmit data for communication system. 256-ary pulse position modulation (PPM) using intensity modu- lation with direct detection (IM/DD) as a power efficient system is employed using PIN receiver. Obtained results demonstrate that significant boost of data rate can be achieved using MIMO techniques. Data rate enhances from 350 Mbps to 800 Mbps when using 2×2 MIMO configuration. As well, 1 Gbps is reported for 4 × 4 MIMO system. These enhancements are achieved without any bandwidth or power expansions and the bit error rate (BER) at the receiver is maintained below 10−3

MIMO Techniques for High Data Rate Free Space Optical Communication System in Log-Normal Channel

Abstract—Multiple input multiple output (MIMO) technique with equal gain combining (EGC) is considered in this work to enhance the data rate of free-space optical communication (FSO) system in log-normal channel. In FSO system, light propagating in free space is used to transmit data for communication system. 256-ary pulse position modulation (PPM) using intensity modulation with direct detection (IM/DD) as a power efficient system is employed using PIN receiver. Obtained results demonstrate that significant boost of data rate can be achieved using MIMO techniques. Data rate enhances from 350 Mbps to 800 Mbps when using 2×2 MIMO configuration. As well, 1 Gbps is reported for 4×4 MIMO system. These enhancements are achieved without any bandwidth or power expansions and the bit error rate (BER) at the receiver is maintained below 10 −3. Index Terms—Free-space optical communications (FSO), M-ary pulse position modulation (M-ary PPM), Multiple input multiple output (MIMO), Log-normal channel, PIN receiver. I