Typically researchers in the Image Science and Analysis Group at the Johnson Space Center provide analyses of images of spacecraft hardware for engineers. Recently, however, they were able to use their expertise to help law enforcement agencies by enhancing photos and videos of crime scenes.
Friendswood Police Department and Pasadena Arson Division came to NASA for help. NASA researchers captured still images and digital movies from videotapes provided by investigators and performed enhancements of that imagery to bring out details that were not readily apparent in the original.
"Our enhancements of the original imagery helped these law enforcement agencies obtain indictments and even confessions from suspects," said Mike Snyder, Lockheed Martin project manager for the JSC Image Science and Analysis Group.
The group reduced image "noise" and enhanced detail. This multi-step process includes de-interlacing video frames, selecting appropriate sequences and then carefully aligning multiple single images and adding or averaging them together to create a composite. The averaging of the single images is a common technique used by astronomers to reduce background noise in observations.
"We digitally enhanced video images to help identify vehicles and/or suspect attributes such as faces and clothing," said David Bretz, a senior scientist for Hernandez Engineering in the JSC Image Science and Analysis Group. "In the Friendswood case, we helped identify a suspect's vehicle that was observed by a security camera near the scene where a shooting was later reported. We also helped establish that nobody was observed fleeing the scene.
"In the Pasadena case, we enhanced images of a repeat arsonist caught by a video camera set up overnight by the victims. It was just enough improvement so that the victims could positively identify the person, which led to his arrest and a written confession."
Eric Nielsen, the computer system administrator for Hernandez Engineering, helped Bretz on both cases. "Working with crime investigation video really pushes our image enhancement capabilities. The video we normally receive is very poor, requiring us to experiment with different enhancement techniques. These challenges benefit our group because they press us to extend our expertise and, at the same time, we are providing a valuable service to law enforcement agencies. It is also very satisfying when our efforts help to resolve a case."
The researchers received a letter of commendation from the City of Pasadena for their efforts.
"I commend the JSC Image Science and Analysis Group for all its hard work and effort," said Debbie Taylor, arson investigator, Pasadena Arson Division. "This case might not have been solved otherwise."
Friendswood Police Department was equally commending. "Without the help from the Image Science and Analysis Group, we wouldn't have had a case. Now we have a very good case," said Eric Price, criminal investigator with the department.
JSC's Image Science and Analysis Group specializes in making quantitative measurements and qualitative enhancements of imagery for programs like the space shuttle, the space station and the Hubble Space Telescope. This same image analysis can also be applied to forensic analysis.
"Generally, we have limited control over how imagery is acquired, and often become involved only after an event has been observed, so the challenges are similar to those facing crime investigators," Bretz said. "We try to maintain a broad range of tools and techniques for squeezing information out of the images we receive."
The group has worked with law enforcement agencies in the past to help solve crimes. In an arson case for the Harris County Fire and Emergency Services Department, an enhanced video image was made of a suspect observed during a repeat crime. When the suspect was shown the image, he confessed immediately.
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