Laser speckle decorrelation for fingerprint acquisition

Biometry is gaining popularity as a physical security approach in situations where a high level of security is necessary. Currently, biometric solutions are embedded in a very large and heterogeneous group of applications. One of the most sensible is for airport security access to boarding gates. More airports are introducing biometric solutions based on face, fingerprint or iris recognition for passenger identification. In particular, fingerprints are the most widely used biometric, and they are mandatorily included in electronic identification documents. One important issue, which is difficult to address in traditional fingerprint acquisition systems, is preventing contact between subsequent users; sebum, which can be a potential vector for contagious diseases. Currently, non-contact devices are used to overcome this problem. In this paper, a new contact device based on laser speckle decorrelation is presented. Our system has the advantage of being compact and low-cost compared with an actual contactless system, allowing enhancement of the sebum pattern imaging contrast in a simple and low-cost way. Furthermore, it avoids the spreading of contagious diseases

Biometric-Like Approach for Verifying Artworks Authenticity

The artwork market is plenty of unauthorized reproduction of original products. One of the most varies filed is the counterfeiting of Authenticity Certificate related to paints, lithography, sculptures, etc., with the aim to create an illegal market of reproduced copies. To resolve this problematic, it is possible change the current paper certificate, related to a single artwork, with a digital version, which will contain some specific information, related to the artwork itself. In this paper, starting with the well-known advantages given by the biometry paradigm in human authentication, we propose a method able to distinguish the single “non-living” objects. In other words, we propose an approach that, by using the random inimitably characteristics, is able to uniquely identify artworks such as painting, lithographs, sculptures, etc. In this way it could be possible creating a secure digital certificate of authenticity (digital COA). Due to the high density information available in modern acquisition media, it is possible using a Speckle Metrology approach. During verification phase, the same area has to be acquired, to extract embedded verification data. It is possible to secure this data using a private key, necessary for accepting the digital signature. The presence of possible geometrical distortions between image present in the certificate and acquired during the verification phase, it is necessary applying geometrical corrections based on affine transformation, before executing the correlation methodologies, used in speckle metrology

Content fragile watermarking based on a computer generated hologram coding technique

In this paper we present a content fragile watermarking based on a computer generated hologram coding technique. Content fragile watermarking techniques aim to prevent tampering and fraudulent use of modified images. A content fragile watermark monitors the integrity of the content of the image but not its numerical representation. Therefore, the watermark is designed so that the integrity is proven if the content of the image has not been tampered with. However, if parts of the image are replaced, the watermark information should indicate evidence of forgery. Using computer generated hologram watermarking, the embedded mark could be easily recovered by means of a Fourier transform. Due to this fact the host image can be tampered with and watermarked with the same holographic pattern. To avoid this possibility we have introduced an encryption method using a private key. The proposed technique is suitable for use for freelancers’ photography authentication. It could be applied to colour images as well as to grey-scale ones. The proposed schema is based on the knowledge of the original mark from the authentication entity, to apply image correlation between this and the extracted one

Superposed strokes analysis by conoscopic holography as an aid for a handwriting expert

For legal purposes there is a requirement for the validation of signatures and handwritten documents. A helpful method in this respect is the so-called superposed strokes analysis, based on the observation of some characteristics in the writing, such as some letters and their dynamics. This paper introduces a promising new technique for superposed strokes analysis based on conoscopic holography. Through a non-contact 3D measure a 3D profile is created of the superposed strokes that allows the writing dynamics to be determined, such as, for example, if a stroke was drawn clockwise or counterclockwise. We propose a 3D analysis by an opto-electronic system, in order to improve the graphology analysis for off-line signature verification

Fringe-projection profilometry for recovering 2.5D shape of ancient coins

The form of relief is undoubtedly one of the most topical subjects in the field of cultural heritage. Physical access to historic and artistic products can be limited by a number of factors. For example, access to collections of ancient coins is difficult, especially for students. Indeed, coin digital archives containing high-quality three-dimensional models and that can be accessed remotely are of great interest. The use of projected fringes for the measurement of surface profiles is a well-developed technique. In this paper, we present a surface-profile measurement system for small cultural heritage objects where it is important not only to detect the shape with a high degree of accuracy but also to capture and archive any signs of ageing. The equipment presented in this paper is simple, reliable and cheap. In addition, some examples are presented to demonstrate the potential of the proposed scheme for recovering 2.5D shapes of cultural heritage objects

A Brief Survey on Underwater Optical Wireless Communications

Acoustic, radio frequency (RF) and optical waves systems are the technologies that are used to carry out underwater wireless communications. In scientific, military and industrial sectors, the development of robust and efficient submarine wireless communication links is of enormous interest. To achieve secure short-range wireless communications, the Underwater Optical Wireless Communication (UOWC), which uses the 450-550 nm spectral range of the electromagnetic spectrum, is a good technology. Recently, UOWC applications have been proposed for environmental monitoring, offshore exploration, and military operations. There are many review articles published on this topic. However, research in this field evolves rapidly as does existing literature. The article deals with current and potentially available UWOC technologies in the near future. It is aimed at those who want to undertake studies in this field. Obviously, this paper does not attempt to cover every single aspect of UWOC

Is it possible to use biometric techniques as authentication solution for objects? Biometry vs. hylemetry

Biometry is a wide-used and pervasive approach to verify people identity, based on the presence of some unique characteristics, having precise properties (i.e. biometric characteristics). On the other hand, optical detection of random features is widely used for recognizing object authenticity. In this paper we explain how these two approaches are similar; random features can be seen as "fingerprint" of inanimate objects. Some parallelisms with well-known biometrics solutions are reported, to emphasize the similarity of the two approaches

Underwater optical wireless communications: Overview

Underwater Optical Wireless Communication (UOWC) is not a new idea, but it has recently attracted renewed interest since seawater presents a reduced absorption window for blue-green light. Due to its higher bandwidth, underwater optical wireless communications can support higher data rates at low latency levels compared to acoustic and RF counterparts. The paper is aimed at those who want to undertake studies on UOWC. It offers an overview on the current technologies and those potentially available soon. Particular attention has been given to offering a recent bibliography, especially on the use of single-photon receivers