We all know that hand held camera shots cause jittery video, but imagine how much worse it would be if you were filming something 93 million miles away. NASA spacecraft do it all the time.
Now NASAs solution for getting rid of the jitters is being used for a different purpose altogether—fighting crime. The system has already helped solve a murder and will soon be available for the FBI and police to use on their own computers.
Getting rid of the jitters
Video Image Stabilization and Registration, or VISAR, was invented by David Hathaway and Paul Meyer, scientists at NASAâ€™s Marshall Space Flight Center in Huntsville, Alabama. VISAR is able to correct for horizontal and vertical camera motion, as well as rotations and zoom effects. Sequences wonâ€™t move by more than one-tenth of a pixel, Hathaway says. "We keep rotations to less than a thirtieth of a degree and we keep the zoom factor steady to within one part in a thousand," he explains. The system also eliminates jagged edges from still images taken from video, reduces "snow" (static), and deblurs images.
They originally developed it for stabilizing remote images shot by spacecraft and satellites. "When I analyze images of the Sun I need to take care of shaking of the telescope, so itâ€™s usually translations in the horizontal or vertical and thatâ€™s sufficient for most of the images Iâ€™ve had to deal with in my field of work," says Hathaway. But now theyâ€™ve set their sights on Earth.
|VISAR took a single frame from this piece of video—shot in the dark—added multiple frames to the single image, brightened it, and revealed a person (a thief?!?) in the room.|
image: NASA Marshall Space Flight Center
Their foray into forensics began four years ago with the bombing at the Atlanta Olympics that killed two people and injured hundreds more.
"When the FBI came to us with their video from the bombing at the Olympics, we had a whole host of other problems. Some of these video were from people walking through the park at night so they were walking along, the camera was rocking back and forth and they were moving towards or away from the subject."
Hathaway and Meyer were able to clarify the images from the Atlanta videotapes shot at night by amateurs with handheld camcorders. Since then theyâ€™ve refined the VISAR technology, working on approximately a dozen criminal cases in the last year alone, including a murder.
"The thing that drove it home for me was when an FBI agent came down from Minnesota with a videotape of a young woman being abducted from a convenience store off the Interstate and at that point we thought, this woman may still be alive," says Hathaway. "Peopleâ€™s lives are at stake in this and itâ€™s quite different from measuring flows on the surface of the Sun. Itâ€™s just heart-wrenching watching that video in and of itself."
Hathaway helped enhance blurry footage from the storeâ€™s security camera to aid police in identifying the kidnapper, but unfortunately the victim was already dead. However, the tape was used as evidence in the trial of the man convicted of killing her.
"After analyzing crime video for detectives and seeing the horrible details of some of these crimes, it gives me great satisfaction that police can use NASA technology to put murderers behind bars," says Hathaway.
At the moment, VISAR works on a general purpose computer and doesnâ€™t work in real-time, says Hathaway. "But speeding it up on a chip, you can make these things considerably faster and this may only be a year or two away," he says.
VISAR is now licensed to companies developing surveillance technology for the FBI and reconnaissance software for the military that will improve the quality of video shot in rugged environments.
It may have other uses as well. Hathaway envisions using VISAR in medicine, to improve the quality of images shot by tiny cameras used in diagnostic and surgical procedures. He and Meyer are already working with the Casey Eye Institute at the Oregon Health Sciences University to analyze cell movements is the eye associated with immune system diseases.
He also thinks it will eventually be available for consumers, since home videos can now be easily edited on home computers. "Having VISAR as a tool for stabilizing those sequences and taking out the jittery motions of the cameraman, or the mistakes that the cameraman will make, will be very helpful to lots of moms and pops around the nation and around the world," he says.
Elsewhere on the web:
American Academy of Forensic Sciences
International Crime Scene Investigators Association
International Forensic Image Enhancement Society
Definitions and Guidelines for the Use of Imaging Technologies in the Criminal Justice System
Scientific Working Group for Imaging Technologies