New technology tracks taggers in Christchurch

By RNZ

Taggers in Christchurch will find it more difficult to escape detection in the future with the adoption of innovative technology by the city to map and track graffiti.

The city council’s Smart Christchurch program manager Michael Healy said the new software analyzes each graffiti photo submitted by the public and contractors to identify and catch repeat offenders.

Cleaning up graffiti costs Christchurch taxpayers nearly a million dollars a year, he said.

“And that’s not including the costs incurred by the owners.”

The council had analyzed international programs that manually matched and tracked graffiti and worked with law enforcement to find criminals, reducing crime by 50 percent.

“We didn’t have the resources to manually review all the photos that came in – we get 20,000 photos a year, most of them through the Snap Send Solve smartphone app.

“So we thought, why can’t we just use software and the images we get to do it automatically and then use that information to work with the police and our graffiti team to make a concerted difference?”

A 12-month trial will begin shortly to test the effectiveness of the Smart Christchurch Graffiti Recognition technology.

“There is evidence that graffiti goes with other antisocial behavior and has a negative effect on neighborhoods,” Healey said.

“If you can stay on top of that and reorient people, mainly young people, in a more positive direction, that will make a difference.”

The council commissioned local company Flock Consulting to develop the software.

Co-founder Hayden Park said one of Flock’s data scientists came up with the creative idea for an algorithm that was less about analyzing the image than it was about combining shapes and contours.

“We ended up with a stylistic combination engine that is quite clever and quite unique.”

Park said city councils across the country struggled with graffiti and others were expected to join the project.

“Now that we’ve done it once, there are some savings that we can gain by finding a solution that will be cheaper across the country, rather than having one council pay the bill to build this solution.”

The “beta version” is ready, but Flock and the city council now plan to develop the software further so that it can automatically load the images submitted by the public and build the database.