Robust Systems Large and Small

Image fusion is a lifesaver

Image fusion, says Rick Blum, reveals the whole picture

As a car pulls up to a checkpoint, soldiers scan driver and passengers, wondering if one of them is hiding a gun. As VIPs line up for a reception with the President, security guards look each person up and down, alert to any clue of malicious intent.

Rick Blum, the Robert W. Wieseman Chair in Electrical Engineering, hopes to equip these soldiers and security guards with a device that can save a few potentially lifesaving seconds in the search for concealed weapons.

Blum and his students have developed algorithms through which image fusion is accomplished in the wavelet transform domain. Their Portable Multi-Sensor Imaging Fusion System (PMSIFS) combines a photo taken by an optical camera with a photo of the same subject taken by a millimeter-wave camera (MMW). The composite photo exposes much more than either photo reveals by itself.

Blum illustrates this application of "image fusion" with a set of three photos, arranged side by side, each showing the same shot of the same three men. The left image, taken with an optical camera, shows the men's faces and clothing. The center image, taken with an MMW camera, shows neither physical features nor clothing, but reveals that the man on the right has a gun underneath his sweater.

On the right is the fused image, which police and military personnel are seeking. It shows enough of the men's clothing and features to tell them apart, and it also reveals the unmistakable outline of a gun under the third man's sweater.

The PMSIFS causes no physical harm to a person and can obtain a photo without a person's knowledge.

Blum, a fellow of IEEE, has been working on image fusion for more than 15 years. His research has been supported by NSF, the Commonwealth of Pennsylvania, AT&T, the U.S. Army Research Office, the Office of Naval Research and the Air Force Office of Scientific Research.

Last year, Blum licensed his technology to SuperVision Technologies Inc. with help from a grant from Pennsylvania's new Keystone Innovation Zone program.

Internet2 enables Lehigh and other NEES schools to conduct multi-site tests

Taking the bite out of earthquakes
Engineers at Lehigh's ATLSS (Advanced Technology for Large Structural Systems) Research Center are leading a national effort to design and test buildings that can survive an earthquake with little or no damage.

In the past 60 years, says ATLSS director Richard Sause, engineers have learned how to build structures that protect occupants and minimize loss of life from earthquakes.

Now engineers are aiming to reduce the property damage and structural "down time" caused by seismic events.

"The building design profession has progressed from the point of accepting building damage in earthquakes, as long as injuries and loss of life are minimized, to the point of seeking significantly reduced damage," says Sause.

"Our research is aiming toward a future where, if you look at a steel-frame building before and after an earthquake, you will see no significant difference."

Much of Lehigh's earthquake-engineering research is funded by NSF through a research program using the George E. Brown Jr. Network for Earthquake Engineering Simulation (NEES), a consortium of 15 universities that includes Lehigh, the University of Illinois, Berkeley and UCLA.

Lehigh's experiments are performed at the ATLSS Center's Real-Time Multi-Directional Testing Facility (RTMD), one of the largest of its kind in the world, which subjects structures to loads and loading rates similar to what they would sustain during earthquakes of the largest magnitudes.

Lehigh is using NEES research funding to develop a variety of systems to enable structures to survive earthquakes. These include braced frames and viscoelastic dampers that absorb seismic forces, columns and beams that bend without breaking while retaining their original position and strength, and steel frames that "self-center" after an earthquake.

Many of these systems direct seismic forces to structural elements that can be replaced quickly and at little cost after an earthquake.

To develop the self-centering frames, ATLSS has received a $2-million grant from NSF and is collaborating with researchers from Princeton, Purdue and the National Center for Research in Earthquake Engineering in Taiwan. The project involves numerical simulations, lab experiments and the use of advanced materials, information technology and advanced sensors. The RTMD facility is equipped with MEMS-based accelerometers, piezoelectric transducers and fiber-optic strain gages.