Purdue researchers launch app to interpret, prevent graffiti

You see it on street signs, along alley ways and on the side of buildings. Graffiti is often the most obvious sign of gang activity in a neighborhood. For law enforcement, it's much more than an eyesore, though.

Purdue researches have created a new app to help law enforcement interpret gang graffiti messages. It's a technology they say could stop crime, before it starts.

"Our technology allows them to take a mobile smart phone, take a picture of the graffiti and get an onboard analysis and interpretation of what they graffiti actually means," said Timothy Collins, Managing Director of Vaccine.

The project is known as GARI or Gang Graffiti Automatic Recognition and Interpretation. It's funded by the U.S. Department of Homeland Security. It was developed by a program called Visual Analytics for Command, Control and Interoperability Environments Center of Excellence, or Vaccine.

"It's a tool that will allow them to analyze and predict and be able to catalog gang activity in their area or in their region," researcher Edward Delp said.

The system uses image analysis algorithms to analyze the graffiti, evaluating features such as colors and shapes of characters. The information is then sent to a server and compared against the graffiti image database.

"They can actually put certain annotation in there. They can also bring up maps. They can say, Ok, I've just taken this image here. Show me all the other gang graffiti images within 500-feet of this picture or all the images taken within the three months or two weeks or whatever," Delp said.

Street graffiti is a common way for gang members to communicate messages, including challenges, warnings or intimidation to rival gangs.

"We've learned a lot. It's very complicated and complex. Basically, it tells a story."

Researchers and law enforcement hope this app will let them in on the conversation.