gallery : Audience

www.chrisoshea.org/projects/audience/

Audience, conceived by rAndom International, is an installation consisting of around 64 head-size mirror objects. Each object moves its head in a particular way to give it different characteristics of human behaviour. Some chat amongst themselves, some shy away and others confidently move to grab your attention.

When members of the audience occupy the space, the mirrors inquisitively follow someone that they find interesting. Having chosen their subject, they all synchronise and turn their heads towards them. Suddenly that person can see their reflection in all of the mirrors. They will watch this person until they become disinterested, then either seek out another subject or return to their private chatter. The collective behaviour of the objects is beyond the control of the viewer, as it is left entirely to their discretion to let go of their subject.

Technical details
Each mirror object can be placed in any location and angle. A calibration set-up stage informs the software of these details. Each mirror is controlled by two servo motors giving it pan and tilt rotations. The mirrors rotate themselves in such a way that enables the viewer to approximately see their face in each mirror.

The chat state is not random movement, but carefully scripted to give each mirror the appearance of different natural behaviors.

An overhead camera provides a live image for analysis. An individual is then tracked using optical flow, to help stick with that person through a crowd.

Mirrors following a person. combination of blob tracking and optical flow points helps to maintain tracking during blob merges and cross over.

Calibration mode. Each mirror can be placed anywhere at any angle. during this setup they all stand up, but one at a time they lie down so they can be seen by the camera. edges help pick them out from the image.