Persistence of Vision – Subverting civil infrastructure

Created by Michael Candy, Persistence of Vision is a public installation that adapts recognisable civil infrastructure into an interactive experience. The project is a reaction to our current state of surveillance, be it self initiated or passive, by revealing an often overlooked or ignored component of our city, and plays on many emerging technologies that are fast embedded into our daily lives, such as AI and computer vision.

Ten CCTV-like units are mounted through the length of the laneway with a (predicted) 120° Pan and 80° tilt, allowing them to ‘pass’ the light beams between each other as pedestrians walk through. Each camera uses DeepStream vision software to detect and track humans as they pass through the laneway. Brushless robotic servo motors enable the pan and tilt axis and an LCD Lens Vector is used to focus the beam when participants are detected. The network is setup to alert neighbouring units of humans approaching. Allowing for the installation to ‘pass’ people between spotlights.

The POV network and cameras must remain constantly powered. The main router contains a Raspberry Pi commanding the network, and each camera contains an Nvidia Jetson Nano computer. Both these computer systems run their operating system from an SD Card. All units are set to power up at 4pm and shut down at midnight. This shutdown involves the camera moving to a set ‘home’ position which is near its centre of pan and then powers down the motors, leaving the LED light on to light the laneway.

When no one is detected, or a detected person is lost each unit will resume a ‘Search Pattern’ in which it pans and tilts through its viewable space in the laneway. Each unit has been setup to limit its movements specific to its space. Early testing showed that some cameras as far as 6 units away were able to detect people in the distance while others like unit 1 were able to spot people walking in the street. These limits can be updated collaboratively as Michael can remote view and control each camera. This involves standing in the desired limit spots and we can change the code on the back end. There is no synchronisation between search patterns and each unit acts as an individual.

Project Page | Michael Candy

Currently exhibited at Slovenska cesta (across Zvezda Park), Zvezda Park & Ribji trg, Ljubljana (11 Sept – 8 Oct 2023) – More Info