X Ray


Project an image onto the underside of a bridge. The image would be of the pipes and cables that run inside the bridges.

Underlying Issue

This would make people aware of some of what it takes for the city to work. It would be like seeing the inside of the bridges with an x-ray kind of view. People would see how important the bridges are for purposes other than just to get across a canal.



A projector would be placed somewhere under the bridge and project up to underside of the bridge.


  • Creation / Acquisition of Image
  • Projector Placement
  • Image Focus and Orientation

If there are pictures available of the internal conduits of the bridges, they are likely not appropriate as they are for use in this manner. An image will likely need to be created specifically for this purpose. This can be based strongly on any pictures that may be available, but will be optimized for visibility and aesthetics. Once an appropriate image has been created or acquired, it will have to be adjusted before being displayed with the projector. The projector will need to be placed at one end of the bridge and project somewhat sideways, so as to not be in the way or be blocked by the boats in the canal. Due to this angle as well as any slope or curvature to the bottom of the bridge, the image will have to be distorted in advance so as to appear properly when projected on the actual surface. Projectors for this purpose will need a reasonable resolution so as to adequately display the modified image. It will also need to be bright enough to reach the far side of the image area, wherever that happens to be on a given bridge. Any projector that is suitable for the M I A installation will be acceptable for this purpose, although this can tolerate somewhat lower projector specifications. Some other potential projectors:

Model List Price Lumens Dimensions (WxLxH) Features / Comments
ViewSonic PJ503D 1 $500 1500 Not Given 800x600 Resolution, 2000:1 Contrast Ratio
Epson PowerLite 77c 2 $750 2200 7.5" x 16.9" x 14.9" 34' Projection Range, 25' Max Image Size, 1024x768 Resolution, 400:1 Contrast Ratio
InFocus IN26+ 3 $750 2400 12" x 9.4" x 4" 33' Projection Range, 21' Max Image Size, 1024x768 Resolution
InFocus Work Big IN10
Ultra-Mobile 3LB 4
$1250 1800 7.8" x 6.1" x 2.5" 22' Max Image Size, 1280x1024 Resolution, 1100:1 Contrast Ratio
Optoma EP729 Micro Portable 5 $1500 1600 6" x 2.46" x 7.87"
2.2 lbs
25' Max Image Size, 1024x768 Resolution, 2200:1 Contrast Ratio
Product Links
1 [http://www.amazon.com/View-Sonic-PJ503D-ViewSonic-Projector/dp/tech-data/B000OLG72U/ref=de_a_smtd?ie=UTF8&qid=1203221060&sr=1-1]
2 [http://www.amazon.com/Epson-PowerLite-Lumen-Multimedia-Projector/dp/tech-data/B000Q5X85I/ref=de_a_smtd?ie=UTF8&qid=1203221060&sr=1-2]
3 [http://www.amazon.com/InFocus-IN26-DLP-Projector-2400/dp/tech-data/B000LNH9FK/ref=de_a_smtd?ie=UTF8&qid=1203221060&sr=1-4]
4 [http://www.amazon.com/InFocus-Work-IN10-Ultra-Mobile-Projector/dp/tech-data/B000SAMJQ0/ref=de_a_smtd?ie=UTF8&qid=1203221060&sr=1-5]
5 [http://www.amazon.com/Optoma-EP729-Portable-Digital-Projector/dp/tech-data/B000A10K72/ref=de_a_smtd?ie=UTF8&qid=1203221060&sr=1-6]

Indoor Implementation

To implement this idea indoors, there could be mock-ups of the bridges and even other parts of Venice set up in the area. These could be screens on which the images of the pipes and such would be projected. Visitors could walk around the area and look at the inner workings of their city. The floor could be decorated so as to resemble the canals and other ground work of Venice. This could simplify the projection by including the background textures in the image and projecting everything onto a white screen, rather than having to compete with an existing texture. These displays would likely be back projected so that the viewers do not block the projections as get close to examine it.

An another possibility for implementation of this idea would focus more on the effect of people walking on the bridges.

Interactive Possibilities

Using a method based on the interactive whiteboard shown on Johnny Lee's website, have the projections be of only the surface of Venice. then provide visitors with a "flashlight" or "X-ray vision" of sorts, and/or a pen or pointer device like those shown in the video. The flashlight could be detected and in the areas where it "shines" the inner workings would be displayed. Somehow in conjunctions with, or possibly instead of the light or x-ray, pointer devices could be used with the mulit-point tracking of the WiiMote to allow the viewers to select an area of the display to bring forward enlarge on the display. If implemented on a small scale, the head tracking (also on Johnny Lee's website), could be used with the pointers to allow for 3D manipulation and viewing of the pipes and such inside the city.


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