Analyses photos of graffiti incidents using machine learning to map and track graffiti offending across Christchurch.
The graffiti recognition app tracks graffiti activity using data from the public and contractors to help curb damage and identify repeat offenders. We analyse each photo using the newly developed graffiti recognition software, and capture key data from the images to help identity and map the activities of recidivist offenders. The data collected and visualised by the solution is used by Council staff, community groups, and NZ Police, to inform decision-making that will reduce graffiti incidents.
Smart Christchurch has worked with Flock Consulting as the delivery partner for the graffiti recognition project. The platform matches graffiti images with other images most similar that have been collected and stored in the application. This enables identification of the most prolific taggers and related tags, creating groups with associated ID’s to be used for later reference. This information can then be utilised by relevant stakeholders.
We explored different feature extraction algorithms and machine learning approaches, then used the images/training data to test models and develop a user-friendly front-end web app to:
The Council receives approximately 20,000 notifications of graffiti incidents from the public each year. The majority come via the ‘Snap Send Solve’ platform, as well as emails and online forms. Investigation done in partnership with the Council’s Graffiti Programme and the Continuous Improvement team highlighted an opportunity to work with an innovative technology partner to develop the capability to analyse images received each year, and capture key data for each incident using machine learning.
Developing an automated graffiti-analysis solution using machine-based learning in a joint partnership with an external vendor is a cost effective and innovative way to counter what is a costly, growing problem for Christchurch.
Council can now use the information captured to map and track graffiti offenders operating across Christchurch. This information is also shared with the police to help build case files on offenders and enable prosecutions to be pursued. As this this is further developed, there will be an opportunity in the future to share and/or license the solution to other authorities in New Zealand and overseas.
Shortlisted for 2021 LGNZ Excellence awards in the Social Wellbeing category
Resilient communities | Liveable city