The Slow Glass I


This is a project for a Media Lab class: New Paradigms for Human-Computer Interaction by Pattie Maes and Hiroshi Ishii. Slow glass was imagined by Bob Shaw in the science-fiction story The Light of other Days. Light travels very slowly in this material so that it takes months or even years for people to see what had been on the other side.

We consider the slow glass as an architectural element that provides a window into another space/time. It changes people’s perception of the surroundings. We tried to make an elegant implementation for the concept. The screen is located in the lobby of the new Media Lab building. One camera captures sequential images of the lobby and tracks the coordinates of people using background subtraction. Another set of cameras on the back of the screen records a panorama of the lobby. Video is played back, a few hours later, according to the relative positioning between a person and the screen. From a user’s perspective, the screen is like transparent, only that through it he sees the past.

The tracking system, powered by OpenCV:

A diagram of perspective simulation:

A video of the concept and the first prototype that we presented in the class review. We are currently working on making it a permanent installation in the Media Lab building:

Tools used: Open Frameworks, OpenCV, iMovie
Collaborator: Polychronis Ypodimatopoulos, Daniel Rosenburg

Map of Paris: Visualizing Urban Transportation


Update: If you are interested in isochronic maps, I have more detailed explaination of the process in my graduate thesis Seeing Differently: Cartography for Subjective Maps Based on Dynamic Urban Data, and the source code (Processing) is on GitHub.

What is your mental map of a city? I bet it’s not measured in miles. This project is part of my work in the SENSEable City’s workshop this semester. In these distorted maps of Paris, the distance between a spot and the city center is not proportional to their geographical distance, but the cost taken to get there.

Standard map vs. driving time map of Paris: the city center expands from congestion, and the edge is denser.

Comparing the isochronic map of Paris under different transportation modes: (unit: minutes, click to zoom in)

Think driving is better? However, if we map the city using carbon footprint as distance: (unit: kg CO2, click to zoom in)

In the workshop I proposed an alternative to Google Maps on smartphone map services. I call it an isogreenic map. This would have a psychological influence on the user when he decides which transportation makes the trip easier:

Made with Processing.
Vector map: openstreetmap.org
Connection data: Google Directions, RATP.com

A demo video that shows how the transformation works: