Side-View Face Recognition

Side-view face recognition is a challenging problem with many applications. Especially in real-life scenarios where the environment is uncontrolled, coping with pose variations up to side-view positions is an important task for face recognition. In this paper we discuss the use of side view face recognition techniques to be used in house safety applications. Our aim is to recognize people as they pass through a door, and estimate their location in the house. Here, we compare available databases appropriate for this task, and review current methods for profile face recognition

A Multi-Scale Approach to Directional Field Estimation

This paper proposes a robust method for directional field estimation from fingerprint images that combines estimates at multiple scales. The method is able to provide accurate estimates in scratchy regions, while at the same time maintaining correct estimates around singular points. Compared to other methods, the penalty for detecting false singular points is much smaller, because this does not deteriorate the directional field estimate

Conductance studies on different types of Nb/Al, AlOx,(/A1)/Nb Josephson tunnel junctions

The conductance-voltage characteristics of different types of Josephson tunnel junctions have been measured at 4.2 K: symmetric Nb/Al, AlOx/Al/Nb, asymmetric Nb/Al, AlOx/Nb and Nb/Al/AlOx-/AlOx/Nb, containing a double oxidation layer. The symmetric junctions can be described very well by a trapezoidal potential barrier model. The asymmetric junctions show less agreement with theory. In these junctions resistance switching occurs, possibly due to charge trapping. The resistance is lower than in symmetric junctions. The conductance measurements on double oxidation layer junctions show, that this type of junction has an inhomogeneous oxide layer

Preparation and properties of all high Tc SNS-type edge DC SQUIDs

High-Tc SNS-type Josephson junctions and DC SQUIDs were successfully fabricated using hetero-epitaxially grown multilayers of YBa2Cu3Ox and PrBa2 Cu3O. These layers are c-axis oriented, and hence edges of the multilayers give rise to a current flow in the ab-plane between the electrodes of a Josephson junction. The necessary structuring was done by Ar ion beam etching. The individual junctions exhibit a supercurrent up to 80 K. The IcRn product of these junctions usually has a lower limit of 8 mV at 4.2 K. Voltage modulation of the first DC SQUIDs can be observed up to 66 K. The voltage modulation for various bias currents investigated at 4.2 K noise measurements were performed. Details on the fabrication and measurements are presente

Multichannel heart scanner based on high-Tc SQUIDs

A 7-channel magnetometer for magnetocardiography based on high-T c SQUIDs has been realized. This magnetometer is used for test experiments in the development of a multichannel high-Tc SQUID based heart-scanner for clinical applications. The intrinsic noise level of the channels in the 7-channel system is typically 120 fT/¿(Hz) down to 1 Hz. Magnetocardiograms were recorded inside a magnetically shielded room. Introductory experiments were performed on the suppression of noise by combining magnetometers to form planar gradiometers. The noise suppression that can be established appeared to be limited by the imbalance of the gradiometric configuration, which is roughly 2%. This relatively poor balance of the system is caused by inaccuracies in the transfer functions of the individual SQUID magnetometers, and by deviations from the planar geometr

Pitfall of the Detection Rate Optimized Bit Allocation within template protection and a remedy

One of the requirements of a biometric template protection system is that the protected template ideally should not leak any information about the biometric sample or its derivatives. In the literature, several proposed template protection techniques are based on binary vectors. Hence, they require the extraction of a binary representation from the real- valued biometric sample. In this work we focus on the Detection Rate Optimized Bit Allocation (DROBA) quantization scheme that extracts multiple bits per feature component while maximizing the overall detection rate. The allocation strategy has to be stored as auxiliary data for reuse in the verification phase and is considered as public. This implies that the auxiliary data should not leak any information about the extracted binary representation. Experiments in our work show that the original DROBA algorithm, as known in the literature, creates auxiliary data that leaks a significant amount of information. We show how an adversary is able to exploit this information and significantly increase its success rate on obtaining a false accept. Fortunately, the information leakage can be mitigated by restricting the allocation freedom of the DROBA algorithm. We propose a method based on population statistics and empirically illustrate its effectiveness. All the experiments are based on the MCYT fingerprint database using two different texture based feature extraction algorithms