Monday, January 31, 2011

CONVERTING 2-D PHOTO INTO 3-D FACE FOR SECURITY APPLICATIONS AND FORENSICS

0 comentarios
It is possible to construct a three-dimensional, 3D, face from flat 2D images, according to research published in the International Journal of Biometrics this month. The discovery could be used for biometrics in security applications or in forensic investigations.

Xin Guan and Hanqi Zhuang of Florida Atlantic University on Boca Raton explain how Biometrics, the technology of performing personal identification or authentication via an individual's physical attributes, is becoming an increasingly viable solution for identity management, information protection and homeland security. The researchers have now developed a computer algorithm that can analyze the viewing angle and illumination of a face in an image and generate a 3D view of the face based on the results.

The team points out that while our faces are all different they share so many characteristics that it is difficult for current computer technology to uniquely identify an individual from a flat, 2D image. However, a processed 2D image that yields a 3D image of the face would give a unique perspective.

A 3D image of a person's face might be used in biometrics alongside or instead of fingerprint, iris, face, voice and DNA, recognition techniques for so-called identity management and in security, coupled with smart cards and passwords computer recognition of a real face based on a 3D version of known personnel in a security database could be used to reduce false identification. The same technique might also be applied to analysis of security footage from closed-circuit television cameras (CCTV) in crime investigation or in searching for missing persons. Ultimately, the same technology might also be adapted by the entertainment industry where 2D images of famous people from the past might be rendered in 3D and so allow a face to be animated.

Inderscience Publishers

KILLER PAPER FOR NEXT-GENERATION FOOD PACKAGING

0 comentarios
Scientists are reporting development and successful lab tests of "killer paper," a material intended for use as a new food packaging material that helps preserve foods by fighting the bacteria that cause spoilage. The paper, described in ACS' journal, Langmuir, contains a coating of silver nanoparticles, which are powerful anti-bacterial agents.

Aharon Gedanken and colleagues note that silver already finds wide use as a bacteria fighter in certain medicinal ointments, kitchen and bathroom surfaces, and even odor-resistant socks. Recently, scientists have been exploring the use of silver nanoparticles — each 1/50,000 the width of a human hair — as germ-fighting coatings for plastics, fabrics, and metals. Nanoparticles, which have a longer-lasting effect than larger silver particles, could help overcome the growing problem of antibiotic resistance, in which bacteria develop the ability to shrug-off existing antibiotics. Paper coated with silver nanoparticles could provide an alternative to common food preservation methods such as radiation, heat treatment, and low temperature storage, they note. However, producing "killer paper" suitable for commercial use has proven difficult.

The scientists describe development of an effective, long-lasting method for depositing silver nanoparticles on the surface of paper that involves ultrasound, or the use of high frequency sound waves. The coated paper showed potent antibacterial activity against E. coli and S. aureus, two causes of bacterial food poisoning, killing all of the bacteria in just three hours. This suggests its potential application as a food packaging material for promoting longer shelf life, they note.

ACS

BETTER LEARNING THROUGH HANDWRITING

0 comentarios

Writing by hand strengthens the learning process. When typing on a keyboard, this process may be impaired.

Associate professor Anne Mangen at the University of Stavanger’s Reading Centre asks if something is lost in switching from book to computer screen, and from pen to keyboard.

The process of reading and writing involves a number of senses, she explains. When writing by hand, our brain receives feedback from our motor actions, together with the sensation of touching a pencil and paper. These kinds of feedback is significantly different from those we receive when touching and typing on a keyboard.

Together with neurophysiologist Jean-Luc Velay at the University of Marseille, Anne Mangen has written an article published in the Advances in Haptics periodical. They have examined research which goes a long way in confirming the significance of these differences.

An experiment carried out by Velay’s research team in Marseille establishes that different parts of the brain are activated when we read letters we have learned by handwriting, from those activated when we recognise letters we have learned through typing on a keyboard. When writing by hand, the movements involved leave a motor memory in the sensorimotor part of the brain, which helps us recognise letters. This implies a connection between reading and writing, and suggests that the sensorimotor system plays a role in the process of visual recognition during reading, Mangen explains.

Other experiments suggest that the brain’s Brocas area is discernibly more activated when we are read a verb which is linked to a physical activity, compared with being read an abstract verb or a verb not associated with any action.

“This also happens when you observe someone doing something. You don’t have to do anything yourself. Hearing about or watching some activity is often enough. It may even suffice to observe a familiar tool associated with a particular physical activity,” Mangen says.

Since writing by hand takes longer than typing on a keyboard, the temporal aspect may also influence the learning process, she adds.

The term ‘haptic’ refers to the process of touching and the way in which we communicate by touch, particularly by using our fingers and hands to explore our surroundings. Haptics include both our perceptions when we relate passively to our surroundings, and when we move and act.

There is a lot of research on haptics in relation to computer games, in which for instance vibrating hand controls are employed. According to Mangen, virtual drills with sound and vibration are used for training dentists.

But there has been very little effort to include haptics within the humanistic disciplines, she explains. In educational science, there is scant interest in the ergonomics of reading and writing, and its potential significance in the learning process.

Mangen refers to an experiment involving two groups of adults, in which the participants were assigned the task of having to learn to write in an unknown alphabet, consisting of approximately twenty letters. One group was taught to write by hand, while the other was using a keyboard. Three and six weeks into the experiment, the participants’ recollection of these letters, as well as their rapidity in distinguishing right and reversed letters, were tested. Those who had learned the letters by handwriting came out best in all tests. Furthermore, fMRI brain scans indicated an activation of the Brocas area within this group. Among those who had learned by typing on keyboards, there was little or no activation of this area.

“The sensorimotor component forms an integral part of training for beginners, and in special education for people with learning difficulties. But there is little awareness and understanding of the importance of handwriting to the learning process, beyond that of writing itself,” Mangen says.

She refers to pedagogical research on writing, which has moved from a cognitive approach to a focus on contextual, social and cultural relations. In her opinion, a one-sided focus on context may lead to neglect of the individual, physiological, sensorimotor and phenomenological connections.

Within the field of psychology, there is an awareness of the danger of paying too much attention on mentality. According to Mangen, perception and sensorimotor now play a more prominent role.

“Our bodies are designed to interact with the world which surrounds us. We are living creatures, geared toward using physical objects - be it a book, a keyboard or a pen - to perform certain tasks,” she says.

Being a media and reading researcher, Anne Mangen is a rare bird within her field of study. And she is very enthusiastic about her collaboration with a neurophysiologist.

“We combine very different disciplines. Velay has carried out some very exciting experiments on the difference between handwriting and the use of keyboards, from a neurophysiologic perspective. My contribution centres on how we – as humans with bodies and brains – experience the writing process, through using different technologies in different ways. And how these technologies’ interfaces influence our experience,” she concludes.

(Photo: University of Stavanger)

University of Stavanger

Followers

Archive

 

Selected Science News. Copyright 2008 All Rights Reserved Revolution Two Church theme by Brian Gardner Converted into Blogger Template by Bloganol dot com